code: function(_silent) {
          if (this.enableHighlight) {
              if (this.tree.singleNodeHighlight) {
                  if (this.tree._currentlyHighlighted) {
                      this.tree._currentlyHighlighted.unhighlight(_silent);
                  }
                  this.tree._currentlyHighlighted = this;
              }
              this.highlightState = 1;
              this._setHighlightClassName();
              if (!this.tree.singleNodeHighlight) {
  				if (this.propagateHighlightDown) {
  					for (var i = 0;i < this.children.length;i++) {
  						this.children[i].highlight(true);
  					}
  				}
  				if (this.propagateHighlightUp) {
  					if (this.parent) {
  						this.parent._childrenHighlighted();
  					}
  				}
  			}
              if (!_silent) {
                  this.tree.fireEvent('highlightEvent',this);
              }
          }
      }
docs: Turns highlighting on node.
  @method highlight
  @param _silent {boolean} optional, don't fire the highlightEvent