@abc.abstractmethod<EOL><INDENT>def get_installations_by_parent_genus_type(self, installation_genus_type):<DEDENT>
return<EOL>
Gets an ``InstallationList`` corresponding to the given installation genus ``Type`` and include any
        additional installations with genus types derived from the specified ``Type``.

        In plenary mode, the returned list contains all known
        installations or an error results. Otherwise, the returned list
        may contain only those installations that are accessible through
        this session.

        :param installation_genus_type: an installation genus type
        :type installation_genus_type: ``osid.type.Type``
        :return: the returned ``Installation`` list
        :rtype: ``osid.installation.InstallationList``
        :raise: ``NullArgument`` -- ``installation_genus_type`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*