'Add an FTPCommand object to the queue.
If it\'s the only thing in the queue, and we are connected and we aren\'t
waiting for a response of an earlier command, the command will be sent
immediately.
@param ftpCommand: an L{FTPCommand}'

def queueCommand(self, ftpCommand):

    self.actionQueue.append(ftpCommand)
    if ((len(self.actionQueue) == 1) and (self.transport is not None) and (self.nextDeferred is None)):
        self.sendNextCommand()
