Initialize form map

def _init_map(self, record_types=None, **kwargs):
        """Initialize form map"""
        osid_objects.OsidObjectForm._init_map(self, record_types=record_types)
        self._my_map['outputScore'] = self._output_score_default
        self._my_map['gradeSystemId'] = str(kwargs['grade_system_id'])
        self._my_map['inputScoreEndRange'] = self._input_score_end_range_default
        self._my_map['inputScoreStartRange'] = self._input_score_start_range_default
        self._my_map['assignedGradebookIds'] = [str(kwargs['gradebook_id'])]