@utilities.arguments_not_none<EOL><INDENT>def get_hierarchies_by_record_type(self, hierarchy_record_type):<DEDENT>
raise errors.Unimplemented()<EOL>
Gets a ``HierarchyList`` corresponding to the given hierarchy record ``Type``.

        The set of hierarchies implementing the given record type are
        returned.In plenary mode, the returned list contains all known
        hierarchies or an error results. Otherwise, the returned list
        may contain only those hierarchies that are accessible through
        this session.

        arg:    hierarchy_record_type (osid.type.Type): a hierarchy
                record type
        return: (osid.hierarchy.HierarchyList) - the returned
                ``Hierarchy`` list
        raise:  NullArgument - ``hierarchy_record_type`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*