 
 		// -- Visitation ------------------------------------------------------
 		
+		/**
+		 * Iterates over the contents of the list, invoking a visitor function
+		 * on each element of the list. The visitor function should return a
+		 * Boolean value: if true the iteration will continue, if false the
+		 * iteration will stop with an early exit.
+		 * @param visitor the visitor function to be invoked on each item
+		 * @param reverse optional flag indicating if the list should be
+		 *  visited in reverse order
+		 * @param filter an optional boolean-valued function indicating which
+		 *  items should be visited
+		 * @return true if the visitation completed, false if an early exit
+		 *  occurred
+		 */		
 		public function visit(visitor:Function, reverse:Boolean=false,
 			filter:Function=null):Boolean
 		{

			return o;
		}
		
		internal function remove(o:Object):Boolean
		{
			if (_map[o] == undefined) return false;

		
		// -- Basic Operations: Contains, Add, Remove, Clear ------------------
		
		/**
		 * Indicates if the given object is contained in this list.
		 * @param o the object to check for containment
		 * @return true if the list contains the object, false otherwise.
		 */
		public function contains(o:Object):Boolean
		{
			return (_map[o] != undefined);
		}
		
		/**
		 * Internal method for adding an object to the list. This method should
		 * be used by the Data class only.
		 * @param o the object to add
		 * @return the added object
		 * @private
		 */
		internal function add(o:Object):Object
		{
			_map[o] = _list.length;
