@return The client-specific id that can be used to mark or identify messages between clients. @see <a href="http://docs.oasis-open.org/amqp/core/v1.0/os/amqp-core-messaging-v1.0-os.html#type-properties">AMQP specification</a>
See Implementation
@return The client-specific id that can be used to mark or identify messages between clients. @see <a href="http://docs.oasis-open.org/amqp/core/v1.0/os/amqp-core-messaging-v1.0-os.html#type-properties">AMQP specification</a>