code: def clean(self, force: bool=False):
          '''Clean closed connections.
  
          Args:
              force: Clean connected and idle connections too.
  
          Coroutine.
          '''
          with (yield from self._lock):
              for connection in tuple(self.ready):
                  if force or connection.closed():
                      connection.close()
                      self.ready.remove(connectionf clean(self, force: bool=False):
          '''Clean closed connections.
  
          Args:
              force: Clean connected and idle connections too.
  
          Coroutine.
          '''
          with (yield from self._lock):
              for connection in tuple(self.ready):
                  if force or connection.closed():
                      connection.close()
                      self.ready.remove(connection)
docs: Clean closed connections.
  
          Args:
              force: Clean connected and idle connections too.
  
          Coroutine.