docs: function OutlineService(options) {
  		this._serviceRegistry = options.serviceRegistry;
  		this._preferences = options.preferences;
  		EventTarget.attach(this);
  		this._serviceRegistration = this._serviceRegistry.registerService("orion.edit.outline", this); //$NON-NLS-0$
  		this._provider = new Deferred();
  		this._providerResolved = false;
  
  		this.filteredProviders = [];
  		//this.setOutlineProviders(this.filteredProviders);
  	}