The key for the Message ID. This is an automatically generated UUID and should never be explicitly set in the header map <b>except</b> in the case of Message deserialization where the serialized Message's generated UUID is being restored.
See Implementation
The key for the Message ID. This is an automatically generated UUID and should never be explicitly set in the header map <b>except</b> in the case of Message deserialization where the serialized Message's generated UUID is being restored.