src/vs/editor/common/model/textModel.ts/TextModel/_hasListeners
class TextModel:	_hasListeners(): boolean {
		return (
			this._onWillDispose.hasListeners()
			|| this._onDidChangeDecorations.hasListeners()
			|| this._tokenizationTextModelPart._hasListeners()
			|| this._onDidChangeOptions.hasListeners()
			|| this._onDidChangeAttached.hasListeners()
			|| this._onDidChangeInjectedText.hasListeners()
			|| this._eventEmitter.hasListeners()
		);
	}