code: def validate_groupby_func(name, args, kwargs, allowed=None):
      
      if allowed is None:
          allowed = []
  
      kwargs = set(kwargs) - set(allowed)
  
      if len(args) + len(kwargs) > 0:
          raise UnsupportedFunctionCall((
              "numpy operations are not valid "
              "with groupby. Use .groupby(...)."
              "{func}() instead".format(func=name)))
docs: 'args' and 'kwargs' should be empty, except for allowed
      kwargs because all of
      their necessary parameters are explicitly listed in
      the function signature