code: def iterfields(klass):
      
      is_field = lambda x: isinstance(x, TypedField)
  
      for name, field in inspect.getmembers(klass, predicate=is_field):
          yield name, field
docs: Iterate over the input class members and yield its TypedFields.
  
      Args:
          klass: A class (usually an Entity subclass).
  
      Yields:
          (class attribute name, TypedField instance) tuples.