Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/mpl_toolkits/tests/__init__.py

@@ -0,0 +1,10 @@
+from pathlib import Path
+
+
+# Check that the test directories exist
+if not (Path(__file__).parent / "baseline_images").exists():
+    raise IOError(
+        'The baseline image directory does not exist. '
+        'This is most likely because the test data is not installed. '
+        'You may need to install matplotlib from source to get the '
+        'test data.')