def get_gradebooks(self):
<EOL>if self._catalog_session is not None:<EOL><INDENT>return self._catalog_session.get_catalogs()<EOL><DEDENT>collection = JSONClientValidated('<STR_LIT>',<EOL>collection='<STR_LIT>',<EOL>runtime=self._runtime)<EOL>result = collection.find().sort('<STR_LIT>', DESCENDING)<EOL>return objects.GradebookList(result, runtime=self._runtime, proxy=self._proxy)<EOL>
Gets all ``Gradebooks``.

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

        return: (osid.grading.GradebookList) - a ``GradebookList``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*