def get_source_types_by_destination_and_relation_type(self, destination_type=None, relation_type=None):
raise Unimplemented()<EOL>
Gets all source Types related to the given destination ``Type`` and relation ``Type``.

        arg:    destination_type (osid.type.Type): a destination type
        arg:    relation_type (osid.type.Type): a relation type
        return: (osid.type.TypeList) - the related types
        raise:  NullArgument - ``destination_type`` or ``relation_type``
                is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*