Class MandatoryMutableDisposable

src/vs/base/common/lifecycle.ts:563–586

 * exist and cannot be undefined.
 */
export class MandatoryMutableDisposable<T extends IDisposable> implements IDisposable {
	private readonly _disposable = new MutableDisposable<T>();
	private _isDisposed = false;

	constructor(initialValue: T) {
		this._disposable.value = initialValue;
	}

	get value(): T {
		return this._disposable.value!;
	}

	set value(value: T) {
		if (this._isDisposed || value === this._disposable.value) {
			return;
		}
		this._disposable.value = value;
	}

	dispose() {
		this._isDisposed = true;
		this._disposable.dispose();
	}
}

export class RefCountedDisposable {