docs: def validate_json(self, json_value, validator):
          """Validates and returns the parsed JSON string.
  
          If the value is not valid JSON, ParseError will be raised. If it is
          valid JSON, but does not validate against the schema,
          SchemaValidationError will be raised.
  
          :param str json_value: JSON value.
          :param validator: An instance of a jsonschema validator class, as
              created by Schema.get_validator().
          :returns: the parsed JSON value.
          """
          value = parse_json(json_value)
          return self.validate(value, validator)