code: def _validate_json_format(self, filter_value, schema_validation_type):
          
          ok = False
          try:
              validators.json_schema_validation_format(filter_value, schema_validation_type)
              ok = True
          except ValueError as e:
              pass
          return ok
docs: adds the type:string format:schema_validation_type
          :param filter_value: value of the filter
          :param schema_validation_type: format description of the json schema entry