Updated the files.

my-app/node_modules/@angular-devkit/schematics/src/utility/update-buffer.d.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import { BaseException } from '@angular-devkit/core';
+import MagicString from 'magic-string';
+export declare class IndexOutOfBoundException extends BaseException {
+    constructor(index: number, min: number, max?: number);
+}
+/**
+ * Base class for an update buffer implementation that allows buffers to be inserted to the _right
+ * or _left, or deleted, while keeping indices to the original buffer.
+ */
+export declare abstract class UpdateBufferBase {
+    protected _originalContent: Buffer;
+    constructor(_originalContent: Buffer);
+    abstract get length(): number;
+    abstract get original(): Buffer;
+    abstract toString(encoding?: string): string;
+    abstract generate(): Buffer;
+    abstract insertLeft(index: number, content: Buffer, assert?: boolean): void;
+    abstract insertRight(index: number, content: Buffer, assert?: boolean): void;
+    abstract remove(index: number, length: number): void;
+    /**
+     * Creates an UpdateBufferBase instance.
+     *
+     * @param contentPath The path of the update buffer instance.
+     * @param originalContent The original content of the update buffer instance.
+     * @returns An UpdateBufferBase instance.
+     */
+    static create(contentPath: string, originalContent: Buffer): UpdateBufferBase;
+}
+/**
+ * An utility class that allows buffers to be inserted to the _right or _left, or deleted, while
+ * keeping indices to the original buffer.
+ */
+export declare class UpdateBuffer extends UpdateBufferBase {
+    protected _mutatableContent: MagicString;
+    protected _assertIndex(index: number): void;
+    get length(): number;
+    get original(): Buffer;
+    toString(): string;
+    generate(): Buffer;
+    insertLeft(index: number, content: Buffer): void;
+    insertRight(index: number, content: Buffer): void;
+    remove(index: number, length: number): void;
+}