code: def get_prep_value(self, value):
          
          if value is None:
              return None
          else:
              return encoding.smart_text(
                  base64.b64encode(jsonpickle.encode(value).encode()))
docs: Overrides ``models.Field`` method. This is used to convert
          the value from an instances of this class to bytes that can be
          inserted into the database.