SYSML2_ — Syntactic Sugar Notation to Define Payload for Flow Def

Currently, the only way to create payload for flow def is to redefine it explicitly:

flow def SomeFD {
   :>>payload: SomeData;
   end :FirstEndType;
   end :SecondEndType;
}

it would be nice for the same syntactic sugar "of TypeOfPayload" to be available for flow defs as is now available for flow usages:

flow def SomeFD  of SomeData {
   end :FirstEndType;
   end :SecondEndType;
}