code: def close(self):
          '''Close all connections
  
          Return a :class:`~asyncio.Future` called once all connections
          have closed
          '''
          if not self.closed:
              waiters = []
              queue = self._queue
              while queue.qsize():
                  connection = queue.get_nowait()
                  if connection:
                      closed = connection.close()
                      if closed:
                          waiters.append(closed)
              in_use = self._in_use_connections
              self._in_use_connections = set()
              for connection in in_use:
                  if connection:
                      waiters.append(connection.close())
              self._closed = asyncio.gather(*waiters, loop=self._loop)
          return self._closef close(self):
          '''Close all connections
  
          Return a :class:`~asyncio.Future` called once all connections
          have closed
          '''
          if not self.closed:
              waiters = []
              queue = self._queue
              while queue.qsize():
                  connection = queue.get_nowait()
                  if connection:
                      closed = connection.close()
                      if closed:
                          waiters.append(closed)
              in_use = self._in_use_connections
              self._in_use_connections = set()
              for connection in in_use:
                  if connection:
                      waiters.append(connection.close())
              self._closed = asyncio.gather(*waiters, loop=self._loop)
          return self._closed
docs: Close all connections
  
          Return a :class:`~asyncio.Future` called once all connections
          have closed