public class DataLoadingCommandLookup implements IDataLoadingCommandLookup {

		private var _commandsByDataType:Dictionary;

		public function DataLoadingCommandLookup() {
		}

		//---------------------------------------
		// IDataLoadingCommandLookup Implementation
		//---------------------------------------

		public function mapCommandToClass(commandClazz:Class, dataClazz:Class):void
		{
			if(commandsByDataType[dataClazz] != null)
			{
				throw(new IllegalOperationError('Ambiguous mapping: This data class has already been mapped to a command class.'));
			}

			if(isNotACommand(commandClazz))
			{
				throw(new IllegalOperationError('The command class you passed is missing an execute method.'));
			}

			commandsByDataType[dataClazz] = commandClazz;
		}

		public function getCommandForClass(dataClazz:Class):Class
		{
		   return commandsByDataType[dataClazz];
		}


		private function get commandsByDataType():Dictionary
		{
			return _commandsByDataType || (_commandsByDataType = new Dictionary());
		}

		private function isNotACommand(commandClazz:Class):Boolean
		{
			if(describeType(commandClazz).factory.method.(@name == "execute").length() > 0)
			{
				return false;
			}

			return true;
		}

	}