code: function (config, unselect) {
  			
  			var position, choice;
  			
  			// Should we unselect choice if disabling selected choice
  			if (lang.isUndefined(unselect) || !lang.isBoolean(unselect)) { unselect = true; }
  			
  			position = this.getChoicePosition(config);
  			
  			if (position !== -1) {
  				
  				choice = this.choicesList[position];
  				
  				this.disableChoiceNode(choice.node);
  				
  				// Clear if disabling selected choice
  				if (unselect && this.getValue() === choice.value) {
  					this.clear();
  				}
  				
  			}
  			
  		}
docs: Disable a choice
  @param {Object} config An object targeting the choice to disable (e.g. { position : 1 } || { value: 'second' } || { label: 'Second' })