(runCallback: StringAdd).self
(runCallback: StringFormat).self
(runCallback: ArrowAssoc[RunCallback[T]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(runCallback: Ensuring[RunCallback[T]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
Internal message to compute the provided args (if necessary), invoke the provided callback with the computed args, and send the result to the client.