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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def multi_grade(self, grade_array, gradebook_id=''):
 """Set multiple grades for students. Set multiple student grades for a gradebook. The grades are passed as a list of dictionaries. Each grade dictionary in ``grade_array`` must contain a ``studentId`` and a ``assignmentId``. Options for grade mode are: OVERALL_GRADE = ``1``, REGULAR_GRADE = ``2`` To set 'excused' as the grade, enter ``None`` for ``letterGradeValue`` and ``numericGradeValue``, and pass ``x`` as the ``specialGradeValue``. The ``ReturnAffectedValues`` flag determines whether to return student cumulative points and impacted assignment category grades (average and student grade) .. code-block:: python [ { u'comment': None, u'booleanGradeValue': None, u'studentId': 1135, u'assignmentId': 4522, u'specialGradeValue': None, u'returnAffectedValues': True, u'letterGradeValue': None, u'mode': 2, u'numericGradeValue': 50, u'isGradeApproved': False }, { u'comment': None, u'booleanGradeValue': None, u'studentId': 1135, u'assignmentId': 4522, u'specialGradeValue': u'x', u'returnAffectedValues': True, u'letterGradeValue': None, u'mode': 2, u'numericGradeValue': None, u'isGradeApproved': False }, { u'comment': None, u'booleanGradeValue': None, u'studentId': 1135, u'assignmentId': None, u'specialGradeValue': None, u'returnAffectedValues': True, u'letterGradeValue': u'A', u'mode': 1, u'numericGradeValue': None, u'isGradeApproved': False } ] Args: grade_array (dict):
 an array of grades to save gradebook_id (str):
 unique identifier for gradebook, i.e. ``2314`` Raises: requests.RequestException: Exception connection error ValueError: Unable to decode response content Returns: dict: dictionary containing response ``status`` and ``message`` """

        log.info('Sending grades: %r', grade_array)
        return self.post(
            'multiGrades/{gradebookId}'.format(
                gradebookId=gradebook_id or self.gradebook_id
            ),
            data=grade_array,
        )