code: def _net_write(sock, data, expiration):
      
      current = 0
      l = len(data)
      while current < l:
          _wait_for_writable(sock, expiration)
          current += sock.send(data[current:])
docs: Write the specified data to the socket.
      A Timeout exception will be raised if the operation is not completed
      by the expiration time.