src/vs/editor/browser/services/abstractCodeEditorService.ts/AbstractCodeEditorService/setTransientModelProperty
class AbstractCodeEditorService:	public setTransientModelProperty(model: ITextModel, key: string, value: any): void {
		const uri = model.uri.toString();

		let w: ModelTransientSettingWatcher;
		if (this._transientWatchers.hasOwnProperty(uri)) {
			w = this._transientWatchers[uri];
		} else {
			w = new ModelTransientSettingWatcher(uri, model, this);
			this._transientWatchers[uri] = w;
		}

		w.set(key, value);
		this._onDidChangeTransientModelProperty.fire(model);
	}