parameters: (self, thread)
docstring: Register a thread to join.
  
      Args:
        thread: A Python thread to join.
docstring_summary: Register a thread to join.
docstring_tokens: Register a thread to join .
function: def register_thread(self, thread):
      """Register a thread to join.
  
      Args:
        thread: A Python thread to join.
      """
      with self._lock:
        self._registered_threads.add(thread)
function_tokens: def register_thread ( self , thread ) : with self . _lock : self . _registered_threads . add ( thread )