code: def test_dict_by(xs):
      """dict_by should apply a function to each item in a set to generate the values
      of the returned dict.
  
      """
      m = u.dict_by(xs, len)
  
      # every value is properly constructed
      for k, v in m.items():
          assert len(k) == v
  
      # the key set of the dict is equal to the incoming original set.
      assert set(m.keys()) == xs
  
imports: import itertools
  import json
  import os
  import uuid
  from collections import OrderedDict
  from enum import Enum
  from typing import Union
  import hypothesis.strategies
  from hypothesis import given
  import caliban.util
  import pytest
label_desc: Use image node_id 14 for calling a global function with example usage: test_dict_by(xs) without return types