old_contents: import gevent
  from kvclient import KeyValueClient
  
  
  class TestClient(KeyValueClient):
      yield_loop = gevent.sleep
  
new_contents: import gevent
  from kvclient import KeyValueClient
  
  
  class TestClient(KeyValueClient):
      yield_loop = lambda: gevent.sleep(0)
  
subject: Fix gevent.sleep not having a parameter.