Get the message code for the most recently encountered synchronization command. An NSNumber object that specifies the most recently encountered synchronization command.
This property works with setObject:forProperty:error:.
Available in Mac OS X v10.5 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)