code: function() {
  
  			// ensure only TreeBindings are enhanced which have not been enhanced yet
  			if (!(this instanceof TreeBinding) || this._bIsAdapted) {
  				return;
  			}
  
  			TreeBindingAdapter.apply(this);
  
  			// apply the methods of the adapters prototype to the TreeBinding instance
  			for (var fn in ClientTreeBindingAdapter.prototype) {
  				if (ClientTreeBindingAdapter.prototype.hasOwnProperty(fn)) {
  					this[fn] = ClientTreeBindingAdapter.prototype[fn];
  				}
  			}
  
  			this._invalidTree = true;
  
  			// TODO: Decide if the tree state feature should be available for ClientModels
  			//-> remove comments if yes
  
  			// restore old tree state if given
  			//if (this.mParameters.treeState) {
  			//	this.setTreeState(this.mParameters.treeState);
  			//}
  
  			//set the default auto expand mode
  			this.setNumberOfExpandedLevels(this.mParameters.numberOfExpandedLevels || 0);
  		}
docs: Adapter for TreeBindings to add the ListBinding functionality and use the
  tree structure in list based controls.
  
  @alias sap.ui.model.ClientTreeBindingAdapter
  @class
  @experimental This module is only for experimental use!
  @protected