'Queue the command until the connection is ready to write to again.'

def _queue_command(self, cmd):

    logger.info('[%s]    Queing    as    conn    %r,    cmd:    %r', self.id(), self.state, cmd)
    self.pending_commands.append(cmd)
    if (len(self.pending_commands) > self.max_line_buffer):
        logger.error('[%s]    Remote    failed    to    keep    up', self.id())
        self.send_command(ErrorCommand('Failed    to    keep    up'), do_buffer=False)
        self.close()
