internal override DeleteEFElementCommand GetDeleteCommand()
        {
            var cmd = new DeleteFunctionMappingCommand(this);

            if (cmd == null)
            {
                // shouldn't happen, just to be safe
                throw new InvalidOperationException();
            }
            return(cmd);
        }
        internal static DeleteEFElementCommand GetDeleteCommand(
            EntityType conceptualEntityType, Function function, ModificationFunctionType type)
        {
            var cmd = new DeleteFunctionMappingCommand(conceptualEntityType, function, type);

            if (cmd == null)
            {
                // shouldn't happen, just to be safe
                throw new InvalidOperationException();
            }
            return(cmd);
        }