src/vs/workbench/common/editor/textEditorModel.ts/BaseTextEditorModel/registerModelDisposeListener
class BaseTextEditorModel:	private registerModelDisposeListener(model: ITextModel): void {
		this.modelDisposeListener.value = model.onWillDispose(() => {
			this.textEditorModelHandle = undefined; // make sure we do not dispose code editor model again
			this.dispose();
		});
	}