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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 get_question_form_for_update(self, question_id):
 """Gets the question form for updating an existing question. A new question form should be requested for each update transaction. arg: question_id (osid.id.Id):
 the ``Id`` of the ``Question`` return: (osid.assessment.QuestionForm) - the question form raise: NotFound - ``question_id`` is not found raise: NullArgument - ``question_id`` is ``null`` raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure occurred *compliance: mandatory -- This method must be implemented.* """

        collection = JSONClientValidated('assessment',
                                         collection='Item',
                                         runtime=self._runtime)
        if not isinstance(question_id, ABCId):
            raise errors.InvalidArgument('the argument is not a valid OSID Id')
        document = collection.find_one({'question._id': ObjectId(question_id.get_identifier())})
        obj_form = objects.QuestionForm(osid_object_map=document['question'],
                                        runtime=self._runtime,
                                        proxy=self._proxy)
        self._forms[obj_form.get_id().get_identifier()] = not UPDATED
        return obj_form