pauseMessage
Pauses I/O on @msg.
This can be used when you need to return from the server handler without having the full response ready yet. Use method@Server.unpause_message to resume I/O.
This must only be called on a class@ServerMessage which was created by the #SoupServer and are currently doing I/O, such as those passed into a callback@ServerCallback or emitted in a signal@Server::request-read signal.
Parameters
msg
a #SoupServerMessage associated with @server.