docs: def get_body_validator(models):
      """Returns a validator for the request body, based on a
      :class:`jsonschema.validators.Draft4Validator`, with extra validations
      added for swaggers extensions to jsonschema.
  
      :param models: a mapping of reference to models
      :returns: a :class:`jsonschema.validators.Validator` which can validate
          the request body.
      """
      return validators.extend(
          Draft4Validator,
          {
              'paramType': ignore,
              'name': ignore,
              'type': build_swagger_type_validator(models),
              'required': required_validator,
          }
      )