@utilities.arguments_not_none<EOL><INDENT>def get_grade_systems_by_gradebooks(self, gradebook_ids):<DEDENT>
<EOL>grade_system_list = []<EOL>for gradebook_id in gradebook_ids:<EOL><INDENT>grade_system_list += list(<EOL>self.get_grade_systems_by_gradebook(gradebook_id))<EOL><DEDENT>return objects.GradeSystemList(grade_system_list)<EOL>
Gets the list of grade systems corresponding to a list of ``Gradebooks``.

        arg:    gradebook_ids (osid.id.IdList): list of gradebook
                ``Ids``
        return: (osid.grading.GradeSystemList) - list of grade systems
        raise:  NullArgument - ``gradebook_ids`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*