code: def add_key_value(self, key, value):
          
          key = self._metadata_map.get(key, key)
          if key in ['dateAdded', 'lastModified']:
              self._indicator_data[key] = self._utils.format_datetime(
                  value, date_format='%Y-%m-%dT%H:%M:%SZ'
              )
          elif key == 'confidence':
              self._indicator_data[key] = int(value)
          elif key == 'rating':
              self._indicator_data[key] = float(value)
          else:
              self._indicator_data[key] = value
docs: Add custom field to Indicator object.
  
          .. note:: The key must be the exact name required by the batch schema.
  
          Example::
  
              file_hash = tcex.batch.file('File', '1d878cdc391461e392678ba3fc9f6f32')
              file_hash.add_key_value('size', '1024')
  
          Args:
              key (str): The field key to add to the JSON batch data.
              value (str): The field value to add to the JSON batch data.