* Returns one of the volatile fields from the message. The given field name
* is prepended with “volatile.” so if you want to get the value of the
* field with the name “volatile.status” you only need to specify “status”.
* Returns one of the volatile fields from the message. The given field name
* is prepended with “volatile.” so if you want to get the value of the
* field with the name “volatile.status” you only need to specify “status”.