code: function(model) {
  			var rowDiv = this.getRowDiv(model);
  			if (this.isExpandable(model) && this.isExpanded(model)) {
  				this._modelIterator.collapse(model);
  				this.explorer.myTree.toggle(rowDiv.id); // collapse tree visually
  			}
  			rowDiv.classList.remove("checkedRow"); //$NON-NLS-0$
  			rowDiv.classList.add("disabledNavRow"); //$NON-NLS-0$
  			this.setIsNotSelectable(model, true);
  		}
docs: Disables the specified model making it no longer respond
  to user input such as mouse click or key presses. The
  CSS style of corresponding row node is also modified to
  reflect its disabled state.
  
  @param {Object} model