Uploaded Test files

venv/Lib/site-packages/joblib/externals/cloudpickle/cloudpickle.py

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+"""
+This class is defined to override standard pickle functionality
+
+The goals of it follow:
+-Serialize lambdas and nested functions to compiled byte code
+-Deal with main module correctly
+-Deal with other non-serializable objects
+
+It does not include an unpickler, as standard python unpickling suffices.
+
+This module was extracted from the `cloud` package, developed by `PiCloud, Inc.
+<https://web.archive.org/web/20140626004012/http://www.picloud.com/>`_.
+
+Copyright (c) 2012, Regents of the University of California.
+Copyright (c) 2009 `PiCloud, Inc. <https://web.archive.org/web/20140626004012/http://www.picloud.com/>`_.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the University of California, Berkeley nor the
+      names of its contributors may be used to endorse or promote
+      products derived from this software without specific prior written
+      permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""
+from __future__ import print_function
+
+import builtins
+import dis
+import opcode
+import platform
+import sys
+import types
+import weakref
+import uuid
+import threading
+import typing
+import warnings
+
+from .compat import pickle
+from typing import Generic, Union, Tuple, Callable
+from pickle import _getattribute
+from importlib._bootstrap import _find_spec
+
+try:  # pragma: no branch
+    import typing_extensions as _typing_extensions
+    from typing_extensions import Literal, Final
+except ImportError:
+    _typing_extensions = Literal = Final = None
+
+if sys.version_info >= (3, 5, 3):
+    from typing import ClassVar
+else:  # pragma: no cover
+    ClassVar = None
+
+if sys.version_info >= (3, 8):
+    from types import CellType
+else:
+    def f():
+        a = 1
+
+        def g():
+            return a
+        return g
+    CellType = type(f().__closure__[0])
+
+
+# cloudpickle is meant for inter process communication: we expect all
+# communicating processes to run the same Python version hence we favor
+# communication speed over compatibility:
+DEFAULT_PROTOCOL = pickle.HIGHEST_PROTOCOL
+
+# Track the provenance of reconstructed dynamic classes to make it possible to
+# recontruct instances from the matching singleton class definition when
+# appropriate and preserve the usual "isinstance" semantics of Python objects.
+_DYNAMIC_CLASS_TRACKER_BY_CLASS = weakref.WeakKeyDictionary()
+_DYNAMIC_CLASS_TRACKER_BY_ID = weakref.WeakValueDictionary()
+_DYNAMIC_CLASS_TRACKER_LOCK = threading.Lock()
+
+PYPY = platform.python_implementation() == "PyPy"
+
+builtin_code_type = None
+if PYPY:
+    # builtin-code objects only exist in pypy
+    builtin_code_type = type(float.__new__.__code__)
+
+_extract_code_globals_cache = weakref.WeakKeyDictionary()
+
+
+def _get_or_create_tracker_id(class_def):
+    with _DYNAMIC_CLASS_TRACKER_LOCK:
+        class_tracker_id = _DYNAMIC_CLASS_TRACKER_BY_CLASS.get(class_def)
+        if class_tracker_id is None:
+            class_tracker_id = uuid.uuid4().hex
+            _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id
+            _DYNAMIC_CLASS_TRACKER_BY_ID[class_tracker_id] = class_def
+    return class_tracker_id
+
+
+def _lookup_class_or_track(class_tracker_id, class_def):
+    if class_tracker_id is not None:
+        with _DYNAMIC_CLASS_TRACKER_LOCK:
+            class_def = _DYNAMIC_CLASS_TRACKER_BY_ID.setdefault(
+                class_tracker_id, class_def)
+            _DYNAMIC_CLASS_TRACKER_BY_CLASS[class_def] = class_tracker_id
+    return class_def
+
+
+def _whichmodule(obj, name):
+    """Find the module an object belongs to.
+
+    This function differs from ``pickle.whichmodule`` in two ways:
+    - it does not mangle the cases where obj's module is __main__ and obj was
+      not found in any module.
+    - Errors arising during module introspection are ignored, as those errors
+      are considered unwanted side effects.
+    """
+    if sys.version_info[:2] < (3, 7) and isinstance(obj, typing.TypeVar):  # pragma: no branch  # noqa
+        # Workaround bug in old Python versions: prior to Python 3.7,
+        # T.__module__ would always be set to "typing" even when the TypeVar T
+        # would be defined in a different module.
+        #
+        # For such older Python versions, we ignore the __module__ attribute of
+        # TypeVar instances and instead exhaustively lookup those instances in
+        # all currently imported modules.
+        module_name = None
+    else:
+        module_name = getattr(obj, '__module__', None)
+
+    if module_name is not None:
+        return module_name
+    # Protect the iteration by using a copy of sys.modules against dynamic
+    # modules that trigger imports of other modules upon calls to getattr or
+    # other threads importing at the same time.
+    for module_name, module in sys.modules.copy().items():
+        # Some modules such as coverage can inject non-module objects inside
+        # sys.modules
+        if (
+                module_name == '__main__' or
+                module is None or
+                not isinstance(module, types.ModuleType)
+        ):
+            continue
+        try:
+            if _getattribute(module, name)[0] is obj:
+                return module_name
+        except Exception:
+            pass
+    return None
+
+
+def _is_importable(obj, name=None):
+    """Dispatcher utility to test the importability of various constructs."""
+    if isinstance(obj, types.FunctionType):
+        return _lookup_module_and_qualname(obj, name=name) is not None
+    elif issubclass(type(obj), type):
+        return _lookup_module_and_qualname(obj, name=name) is not None
+    elif isinstance(obj, types.ModuleType):
+        # We assume that sys.modules is primarily used as a cache mechanism for
+        # the Python import machinery. Checking if a module has been added in
+        # is sys.modules therefore a cheap and simple heuristic to tell us whether
+        # we can assume  that a given module could be imported by name in
+        # another Python process.
+        return obj.__name__ in sys.modules
+    else:
+        raise TypeError(
+            "cannot check importability of {} instances".format(
+                type(obj).__name__)
+        )
+
+
+def _lookup_module_and_qualname(obj, name=None):
+    if name is None:
+        name = getattr(obj, '__qualname__', None)
+    if name is None:  # pragma: no cover
+        # This used to be needed for Python 2.7 support but is probably not
+        # needed anymore. However we keep the __name__ introspection in case
+        # users of cloudpickle rely on this old behavior for unknown reasons.
+        name = getattr(obj, '__name__', None)
+
+    module_name = _whichmodule(obj, name)
+
+    if module_name is None:
+        # In this case, obj.__module__ is None AND obj was not found in any
+        # imported module. obj is thus treated as dynamic.
+        return None
+
+    if module_name == "__main__":
+        return None
+
+    # Note: if module_name is in sys.modules, the corresponding module is
+    # assumed importable at unpickling time. See #357
+    module = sys.modules.get(module_name, None)
+    if module is None:
+        # The main reason why obj's module would not be imported is that this
+        # module has been dynamically created, using for example
+        # types.ModuleType. The other possibility is that module was removed
+        # from sys.modules after obj was created/imported. But this case is not
+        # supported, as the standard pickle does not support it either.
+        return None
+
+    try:
+        obj2, parent = _getattribute(module, name)
+    except AttributeError:
+        # obj was not found inside the module it points to
+        return None
+    if obj2 is not obj:
+        return None
+    return module, name
+
+
+def _extract_code_globals(co):
+    """
+    Find all globals names read or written to by codeblock co
+    """
+    out_names = _extract_code_globals_cache.get(co)
+    if out_names is None:
+        names = co.co_names
+        out_names = {names[oparg] for _, oparg in _walk_global_ops(co)}
+
+        # Declaring a function inside another one using the "def ..."
+        # syntax generates a constant code object corresonding to the one
+        # of the nested function's As the nested function may itself need
+        # global variables, we need to introspect its code, extract its
+        # globals, (look for code object in it's co_consts attribute..) and
+        # add the result to code_globals
+        if co.co_consts:
+            for const in co.co_consts:
+                if isinstance(const, types.CodeType):
+                    out_names |= _extract_code_globals(const)
+
+        _extract_code_globals_cache[co] = out_names
+
+    return out_names
+
+
+def _find_imported_submodules(code, top_level_dependencies):
+    """
+    Find currently imported submodules used by a function.
+
+    Submodules used by a function need to be detected and referenced for the
+    function to work correctly at depickling time. Because submodules can be
+    referenced as attribute of their parent package (``package.submodule``), we
+    need a special introspection technique that does not rely on GLOBAL-related
+    opcodes to find references of them in a code object.
+
+    Example:
+    ```
+    import concurrent.futures
+    import cloudpickle
+    def func():
+        x = concurrent.futures.ThreadPoolExecutor
+    if __name__ == '__main__':
+        cloudpickle.dumps(func)
+    ```
+    The globals extracted by cloudpickle in the function's state include the
+    concurrent package, but not its submodule (here, concurrent.futures), which
+    is the module used by func. Find_imported_submodules will detect the usage
+    of concurrent.futures. Saving this module alongside with func will ensure
+    that calling func once depickled does not fail due to concurrent.futures
+    not being imported
+    """
+
+    subimports = []
+    # check if any known dependency is an imported package
+    for x in top_level_dependencies:
+        if (isinstance(x, types.ModuleType) and
+                hasattr(x, '__package__') and x.__package__):
+            # check if the package has any currently loaded sub-imports
+            prefix = x.__name__ + '.'
+            # A concurrent thread could mutate sys.modules,
+            # make sure we iterate over a copy to avoid exceptions
+            for name in list(sys.modules):
+                # Older versions of pytest will add a "None" module to
+                # sys.modules.
+                if name is not None and name.startswith(prefix):
+                    # check whether the function can address the sub-module
+                    tokens = set(name[len(prefix):].split('.'))
+                    if not tokens - set(code.co_names):
+                        subimports.append(sys.modules[name])
+    return subimports
+
+
+def cell_set(cell, value):
+    """Set the value of a closure cell.
+
+    The point of this function is to set the cell_contents attribute of a cell
+    after its creation. This operation is necessary in case the cell contains a
+    reference to the function the cell belongs to, as when calling the
+    function's constructor
+    ``f = types.FunctionType(code, globals, name, argdefs, closure)``,
+    closure will not be able to contain the yet-to-be-created f.
+
+    In Python3.7, cell_contents is writeable, so setting the contents of a cell
+    can be done simply using
+    >>> cell.cell_contents = value
+
+    In earlier Python3 versions, the cell_contents attribute of a cell is read
+    only, but this limitation can be worked around by leveraging the Python 3
+    ``nonlocal`` keyword.
+
+    In Python2 however, this attribute is read only, and there is no
+    ``nonlocal`` keyword. For this reason, we need to come up with more
+    complicated hacks to set this attribute.
+
+    The chosen approach is to create a function with a STORE_DEREF opcode,
+    which sets the content of a closure variable. Typically:
+
+    >>> def inner(value):
+    ...     lambda: cell  # the lambda makes cell a closure
+    ...     cell = value  # cell is a closure, so this triggers a STORE_DEREF
+
+    (Note that in Python2, A STORE_DEREF can never be triggered from an inner
+    function. The function g for example here
+    >>> def f(var):
+    ...     def g():
+    ...         var += 1
+    ...     return g
+
+    will not modify the closure variable ``var```inplace, but instead try to
+    load a local variable var and increment it. As g does not assign the local
+    variable ``var`` any initial value, calling f(1)() will fail at runtime.)
+
+    Our objective is to set the value of a given cell ``cell``. So we need to
+    somewhat reference our ``cell`` object into the ``inner`` function so that
+    this object (and not the smoke cell of the lambda function) gets affected
+    by the STORE_DEREF operation.
+
+    In inner, ``cell`` is referenced as a cell variable (an enclosing variable
+    that is referenced by the inner function). If we create a new function
+    cell_set with the exact same code as ``inner``, but with ``cell`` marked as
+    a free variable instead, the STORE_DEREF will be applied on its closure -
+    ``cell``, which we can specify explicitly during construction! The new
+    cell_set variable thus actually sets the contents of a specified cell!
+
+    Note: we do not make use of the ``nonlocal`` keyword to set the contents of
+    a cell in early python3 versions to limit possible syntax errors in case
+    test and checker libraries decide to parse the whole file.
+    """
+
+    if sys.version_info[:2] >= (3, 7):  # pragma: no branch
+        cell.cell_contents = value
+    else:
+        _cell_set = types.FunctionType(
+            _cell_set_template_code, {}, '_cell_set', (), (cell,),)
+        _cell_set(value)
+
+
+def _make_cell_set_template_code():
+    def _cell_set_factory(value):
+        lambda: cell
+        cell = value
+
+    co = _cell_set_factory.__code__
+
+    _cell_set_template_code = types.CodeType(
+        co.co_argcount,
+        co.co_kwonlyargcount,   # Python 3 only argument
+        co.co_nlocals,
+        co.co_stacksize,
+        co.co_flags,
+        co.co_code,
+        co.co_consts,
+        co.co_names,
+        co.co_varnames,
+        co.co_filename,
+        co.co_name,
+        co.co_firstlineno,
+        co.co_lnotab,
+        co.co_cellvars,  # co_freevars is initialized with co_cellvars
+        (),  # co_cellvars is made empty
+    )
+    return _cell_set_template_code
+
+
+if sys.version_info[:2] < (3, 7):
+    _cell_set_template_code = _make_cell_set_template_code()
+
+# relevant opcodes
+STORE_GLOBAL = opcode.opmap['STORE_GLOBAL']
+DELETE_GLOBAL = opcode.opmap['DELETE_GLOBAL']
+LOAD_GLOBAL = opcode.opmap['LOAD_GLOBAL']
+GLOBAL_OPS = (STORE_GLOBAL, DELETE_GLOBAL, LOAD_GLOBAL)
+HAVE_ARGUMENT = dis.HAVE_ARGUMENT
+EXTENDED_ARG = dis.EXTENDED_ARG
+
+
+_BUILTIN_TYPE_NAMES = {}
+for k, v in types.__dict__.items():
+    if type(v) is type:
+        _BUILTIN_TYPE_NAMES[v] = k
+
+
+def _builtin_type(name):
+    if name == "ClassType":  # pragma: no cover
+        # Backward compat to load pickle files generated with cloudpickle
+        # < 1.3 even if loading pickle files from older versions is not
+        # officially supported.
+        return type
+    return getattr(types, name)
+
+
+def _walk_global_ops(code):
+    """
+    Yield (opcode, argument number) tuples for all
+    global-referencing instructions in *code*.
+    """
+    for instr in dis.get_instructions(code):
+        op = instr.opcode
+        if op in GLOBAL_OPS:
+            yield op, instr.arg
+
+
+def _extract_class_dict(cls):
+    """Retrieve a copy of the dict of a class without the inherited methods"""
+    clsdict = dict(cls.__dict__)  # copy dict proxy to a dict
+    if len(cls.__bases__) == 1:
+        inherited_dict = cls.__bases__[0].__dict__
+    else:
+        inherited_dict = {}
+        for base in reversed(cls.__bases__):
+            inherited_dict.update(base.__dict__)
+    to_remove = []
+    for name, value in clsdict.items():
+        try:
+            base_value = inherited_dict[name]
+            if value is base_value:
+                to_remove.append(name)
+        except KeyError:
+            pass
+    for name in to_remove:
+        clsdict.pop(name)
+    return clsdict
+
+
+if sys.version_info[:2] < (3, 7):  # pragma: no branch
+    def _is_parametrized_type_hint(obj):
+        # This is very cheap but might generate false positives.
+        # general typing Constructs
+        is_typing = getattr(obj, '__origin__', None) is not None
+
+        # typing_extensions.Literal
+        is_litteral = getattr(obj, '__values__', None) is not None
+
+        # typing_extensions.Final
+        is_final = getattr(obj, '__type__', None) is not None
+
+        # typing.Union/Tuple for old Python 3.5
+        is_union = getattr(obj, '__union_params__', None) is not None
+        is_tuple = getattr(obj, '__tuple_params__', None) is not None
+        is_callable = (
+            getattr(obj, '__result__', None) is not None and
+            getattr(obj, '__args__', None) is not None
+        )
+        return any((is_typing, is_litteral, is_final, is_union, is_tuple,
+                    is_callable))
+
+    def _create_parametrized_type_hint(origin, args):
+        return origin[args]
+else:
+    _is_parametrized_type_hint = None
+    _create_parametrized_type_hint = None
+
+
+def parametrized_type_hint_getinitargs(obj):
+    # The distorted type check sematic for typing construct becomes:
+    # ``type(obj) is type(TypeHint)``, which means "obj is a
+    # parametrized TypeHint"
+    if type(obj) is type(Literal):  # pragma: no branch
+        initargs = (Literal, obj.__values__)
+    elif type(obj) is type(Final):  # pragma: no branch
+        initargs = (Final, obj.__type__)
+    elif type(obj) is type(ClassVar):
+        initargs = (ClassVar, obj.__type__)
+    elif type(obj) is type(Generic):
+        parameters = obj.__parameters__
+        if len(obj.__parameters__) > 0:
+            # in early Python 3.5, __parameters__ was sometimes
+            # preferred to __args__
+            initargs = (obj.__origin__, parameters)
+
+        else:
+            initargs = (obj.__origin__, obj.__args__)
+    elif type(obj) is type(Union):
+        if sys.version_info < (3, 5, 3):  # pragma: no cover
+            initargs = (Union, obj.__union_params__)
+        else:
+            initargs = (Union, obj.__args__)
+    elif type(obj) is type(Tuple):
+        if sys.version_info < (3, 5, 3):  # pragma: no cover
+            initargs = (Tuple, obj.__tuple_params__)
+        else:
+            initargs = (Tuple, obj.__args__)
+    elif type(obj) is type(Callable):
+        if sys.version_info < (3, 5, 3):  # pragma: no cover
+            args = obj.__args__
+            result = obj.__result__
+            if args != Ellipsis:
+                if isinstance(args, tuple):
+                    args = list(args)
+                else:
+                    args = [args]
+        else:
+            (*args, result) = obj.__args__
+            if len(args) == 1 and args[0] is Ellipsis:
+                args = Ellipsis
+            else:
+                args = list(args)
+        initargs = (Callable, (args, result))
+    else:  # pragma: no cover
+        raise pickle.PicklingError(
+            "Cloudpickle Error: Unknown type {}".format(type(obj))
+        )
+    return initargs
+
+
+# Tornado support
+
+def is_tornado_coroutine(func):
+    """
+    Return whether *func* is a Tornado coroutine function.
+    Running coroutines are not supported.
+    """
+    if 'tornado.gen' not in sys.modules:
+        return False
+    gen = sys.modules['tornado.gen']
+    if not hasattr(gen, "is_coroutine_function"):
+        # Tornado version is too old
+        return False
+    return gen.is_coroutine_function(func)
+
+
+def _rebuild_tornado_coroutine(func):
+    from tornado import gen
+    return gen.coroutine(func)
+
+
+# including pickles unloading functions in this namespace
+load = pickle.load
+loads = pickle.loads
+
+
+# hack for __import__ not working as desired
+def subimport(name):
+    __import__(name)
+    return sys.modules[name]
+
+
+def dynamic_subimport(name, vars):
+    mod = types.ModuleType(name)
+    mod.__dict__.update(vars)
+    mod.__dict__['__builtins__'] = builtins.__dict__
+    return mod
+
+
+def _gen_ellipsis():
+    return Ellipsis
+
+
+def _gen_not_implemented():
+    return NotImplemented
+
+
+def _get_cell_contents(cell):
+    try:
+        return cell.cell_contents
+    except ValueError:
+        # sentinel used by ``_fill_function`` which will leave the cell empty
+        return _empty_cell_value
+
+
+def instance(cls):
+    """Create a new instance of a class.
+
+    Parameters
+    ----------
+    cls : type
+        The class to create an instance of.
+
+    Returns
+    -------
+    instance : cls
+        A new instance of ``cls``.
+    """
+    return cls()
+
+
+@instance
+class _empty_cell_value(object):
+    """sentinel for empty closures
+    """
+    @classmethod
+    def __reduce__(cls):
+        return cls.__name__
+
+
+def _fill_function(*args):
+    """Fills in the rest of function data into the skeleton function object
+
+    The skeleton itself is create by _make_skel_func().
+    """
+    if len(args) == 2:
+        func = args[0]
+        state = args[1]
+    elif len(args) == 5:
+        # Backwards compat for cloudpickle v0.4.0, after which the `module`
+        # argument was introduced
+        func = args[0]
+        keys = ['globals', 'defaults', 'dict', 'closure_values']
+        state = dict(zip(keys, args[1:]))
+    elif len(args) == 6:
+        # Backwards compat for cloudpickle v0.4.1, after which the function
+        # state was passed as a dict to the _fill_function it-self.
+        func = args[0]
+        keys = ['globals', 'defaults', 'dict', 'module', 'closure_values']
+        state = dict(zip(keys, args[1:]))
+    else:
+        raise ValueError('Unexpected _fill_value arguments: %r' % (args,))
+
+    # - At pickling time, any dynamic global variable used by func is
+    #   serialized by value (in state['globals']).
+    # - At unpickling time, func's __globals__ attribute is initialized by
+    #   first retrieving an empty isolated namespace that will be shared
+    #   with other functions pickled from the same original module
+    #   by the same CloudPickler instance and then updated with the
+    #   content of state['globals'] to populate the shared isolated
+    #   namespace with all the global variables that are specifically
+    #   referenced for this function.
+    func.__globals__.update(state['globals'])
+
+    func.__defaults__ = state['defaults']
+    func.__dict__ = state['dict']
+    if 'annotations' in state:
+        func.__annotations__ = state['annotations']
+    if 'doc' in state:
+        func.__doc__ = state['doc']
+    if 'name' in state:
+        func.__name__ = state['name']
+    if 'module' in state:
+        func.__module__ = state['module']
+    if 'qualname' in state:
+        func.__qualname__ = state['qualname']
+    if 'kwdefaults' in state:
+        func.__kwdefaults__ = state['kwdefaults']
+    # _cloudpickle_subimports is a set of submodules that must be loaded for
+    # the pickled function to work correctly at unpickling time. Now that these
+    # submodules are depickled (hence imported), they can be removed from the
+    # object's state (the object state only served as a reference holder to
+    # these submodules)
+    if '_cloudpickle_submodules' in state:
+        state.pop('_cloudpickle_submodules')
+
+    cells = func.__closure__
+    if cells is not None:
+        for cell, value in zip(cells, state['closure_values']):
+            if value is not _empty_cell_value:
+                cell_set(cell, value)
+
+    return func
+
+
+def _make_empty_cell():
+    if False:
+        # trick the compiler into creating an empty cell in our lambda
+        cell = None
+        raise AssertionError('this route should not be executed')
+
+    return (lambda: cell).__closure__[0]
+
+
+def _make_cell(value=_empty_cell_value):
+    cell = _make_empty_cell()
+    if value is not _empty_cell_value:
+        cell_set(cell, value)
+    return cell
+
+
+def _make_skel_func(code, cell_count, base_globals=None):
+    """ Creates a skeleton function object that contains just the provided
+        code and the correct number of cells in func_closure.  All other
+        func attributes (e.g. func_globals) are empty.
+    """
+    # This function is deprecated and should be removed in cloudpickle 1.7
+    warnings.warn(
+        "A pickle file created using an old (<=1.4.1) version of cloudpicke "
+        "is currently being loaded. This is not supported by cloudpickle and "
+        "will break in cloudpickle 1.7", category=UserWarning
+    )
+    # This is backward-compatibility code: for cloudpickle versions between
+    # 0.5.4 and 0.7, base_globals could be a string or None. base_globals
+    # should now always be a dictionary.
+    if base_globals is None or isinstance(base_globals, str):
+        base_globals = {}
+
+    base_globals['__builtins__'] = __builtins__
+
+    closure = (
+        tuple(_make_empty_cell() for _ in range(cell_count))
+        if cell_count >= 0 else
+        None
+    )
+    return types.FunctionType(code, base_globals, None, None, closure)
+
+
+def _make_skeleton_class(type_constructor, name, bases, type_kwargs,
+                         class_tracker_id, extra):
+    """Build dynamic class with an empty __dict__ to be filled once memoized
+
+    If class_tracker_id is not None, try to lookup an existing class definition
+    matching that id. If none is found, track a newly reconstructed class
+    definition under that id so that other instances stemming from the same
+    class id will also reuse this class definition.
+
+    The "extra" variable is meant to be a dict (or None) that can be used for
+    forward compatibility shall the need arise.
+    """
+    skeleton_class = types.new_class(
+        name, bases, {'metaclass': type_constructor},
+        lambda ns: ns.update(type_kwargs)
+    )
+    return _lookup_class_or_track(class_tracker_id, skeleton_class)
+
+
+def _rehydrate_skeleton_class(skeleton_class, class_dict):
+    """Put attributes from `class_dict` back on `skeleton_class`.
+
+    See CloudPickler.save_dynamic_class for more info.
+    """
+    registry = None
+    for attrname, attr in class_dict.items():
+        if attrname == "_abc_impl":
+            registry = attr
+        else:
+            setattr(skeleton_class, attrname, attr)
+    if registry is not None:
+        for subclass in registry:
+            skeleton_class.register(subclass)
+
+    return skeleton_class
+
+
+def _make_skeleton_enum(bases, name, qualname, members, module,
+                        class_tracker_id, extra):
+    """Build dynamic enum with an empty __dict__ to be filled once memoized
+
+    The creation of the enum class is inspired by the code of
+    EnumMeta._create_.
+
+    If class_tracker_id is not None, try to lookup an existing enum definition
+    matching that id. If none is found, track a newly reconstructed enum
+    definition under that id so that other instances stemming from the same
+    class id will also reuse this enum definition.
+
+    The "extra" variable is meant to be a dict (or None) that can be used for
+    forward compatibility shall the need arise.
+    """
+    # enums always inherit from their base Enum class at the last position in
+    # the list of base classes:
+    enum_base = bases[-1]
+    metacls = enum_base.__class__
+    classdict = metacls.__prepare__(name, bases)
+
+    for member_name, member_value in members.items():
+        classdict[member_name] = member_value
+    enum_class = metacls.__new__(metacls, name, bases, classdict)
+    enum_class.__module__ = module
+    enum_class.__qualname__ = qualname
+
+    return _lookup_class_or_track(class_tracker_id, enum_class)
+
+
+def _make_typevar(name, bound, constraints, covariant, contravariant,
+                  class_tracker_id):
+    tv = typing.TypeVar(
+        name, *constraints, bound=bound,
+        covariant=covariant, contravariant=contravariant
+    )
+    if class_tracker_id is not None:
+        return _lookup_class_or_track(class_tracker_id, tv)
+    else:  # pragma: nocover
+        # Only for Python 3.5.3 compat.
+        return tv
+
+
+def _decompose_typevar(obj):
+    try:
+        class_tracker_id = _get_or_create_tracker_id(obj)
+    except TypeError:  # pragma: nocover
+        # TypeVar instances are not weakref-able in Python 3.5.3
+        class_tracker_id = None
+    return (
+        obj.__name__, obj.__bound__, obj.__constraints__,
+        obj.__covariant__, obj.__contravariant__,
+        class_tracker_id,
+    )
+
+
+def _typevar_reduce(obj):
+    # TypeVar instances have no __qualname__ hence we pass the name explicitly.
+    module_and_name = _lookup_module_and_qualname(obj, name=obj.__name__)
+    if module_and_name is None:
+        return (_make_typevar, _decompose_typevar(obj))
+    return (getattr, module_and_name)
+
+
+def _get_bases(typ):
+    if hasattr(typ, '__orig_bases__'):
+        # For generic types (see PEP 560)
+        bases_attr = '__orig_bases__'
+    else:
+        # For regular class objects
+        bases_attr = '__bases__'
+    return getattr(typ, bases_attr)
+
+
+def _make_dict_keys(obj):
+    return dict.fromkeys(obj).keys()
+
+
+def _make_dict_values(obj):
+    return {i: _ for i, _ in enumerate(obj)}.values()
+
+
+def _make_dict_items(obj):
+    return obj.items()