code: def validate(
              self, schema_id, validation_function=None,
              validation_error_handler=None):
          
  
          if validation_function is None:
              validation_function = self.validation_function
  
          if validation_error_handler is None:
              validation_error_handler = self.validation_error_handler
  
          def decorator(func):
              @wraps(func)
              def wrapper(*args, **kwargs):
                  specs = get_schema_specs(schema_id, self)
                  validate(
                      schema_id=schema_id, specs=specs,
                      validation_function=validation_function,
                      validation_error_handler=validation_error_handler)
                  return func(*args, **kwargs)
  
              return wrapper
  
          return decorator
docs: A decorator that is used to validate incoming requests data
          against a schema
  
              swagger = Swagger(app)
  
              @app.route('/pets', methods=['POST'])
              @swagger.validate('Pet')
              @swag_from("pet_post_endpoint.yml")
              def post():
                  return db.insert(request.data)
  
          This annotation only works if the endpoint is already swagged,
          i.e. placing @swag_from above @validate or not declaring the
          swagger specifications in the method's docstring *won't work*
  
          Naturally, if you use @app.route annotation it still needs to
          be the outermost annotation
  
          :param schema_id: the id of the schema with which the data will
              be validated
  
          :param validation_function: custom validation function which
              takes the positional arguments: data to be validated at
              first and schema to validate against at second
  
          :param validation_error_handler: custom function to handle
              exceptions thrown when validating which takes the exception
              thrown as the first, the data being validated as the second
              and the schema being used to validate as the third argument