docs: function() {
  		if (gui.Client.hasMutations) {
  			if (!this._observer) {
  				var Observer = this._mutationobserver();
  				this._observer = new Observer(function(mutations) {
  					mutations.forEach(function(mutation) {
  						gui.DOMObserver._handleMutation(mutation);
  					});
  				});
  			}
  			this._connect(true);
  			this.observes = true;
  		} else {
  			throw new Error('MutationObserver no such thing');
  		}
  	}