NodeBody

The body of a FunctionNode set through FunctionNode.Builder.body; it runs on the workflow's coroutine, so it must not block, and asynchronous work belongs in a BasePublisherNode. input arrives as the node's input type, in JSON form on an untyped port (a whole number as a Long, a fraction as a Double, an object as a Map), or as a Content message, and may be a predecessor's own collection, so the body must not mutate it. Return null for no output, a value of the output type, or an Event to emit as it is (an Event with content sends a message, and an output goes in the return value, not in the Event), and ask the user with requestInput.