(Информация о версии неизвестна, возможно, только в SVN)
AMQPEnvelope::isRedelivery — Whether this is a redelivery of the message
Whether this is a redelivery of a message. If this message has been delivered and AMQPEnvelope::nack() was called, the message will be put back on the queue to be redelivered, at which point the message will always return TRUE when this method is called.
У этой функции нет параметров.
TRUE if this is a redelivery, FALSE otherwise.