docs: function(visible, force) {
  			if (this._annotationRulerVisible === visible && !force) { return; }
  			this._annotationRulerVisible = visible;
  			if (!this._annotationRuler) { return; }
  			var textView = this._textView;
  			if (visible) {
  				textView.addRuler(this._annotationRuler, 0);
  			} else {
  				textView.removeRuler(this._annotationRuler);
  			}
  		}