old_contents: import pickletools
  from test import test_support
  test_support.run_doctest(pickletools)
  
new_contents: import pickle
  import pickletools
  from test import test_support
  from test.pickletester import AbstractPickleTests
  from test.pickletester import AbstractPickleModuleTests
  
  class OptimizedPickleTests(AbstractPickleTests, AbstractPickleModuleTests):
  
      def dumps(self, arg, proto=0, fast=0):
          return pickletools.optimize(pickle.dumps(arg, proto))
  
      def loads(self, buf):
          return pickle.loads(buf)
  
      module = pickle
      error = KeyError
  
  def test_main():
      test_support.run_unittest(OptimizedPickleTests)
      test_support.run_doctest(pickletools)
  
  
  if __name__ == "__main__":
      test_main()
  
subject: Add tests for pickletools.optimize().