+ return
+ chatHome
+ .getChatroom(chatroomId)
+ .map(chatroom -> put(chatroom, username, messageId, text))
+ .orElseThrow(() -> new UnknownChatroomException(chatroomId));
+ }
+
+ public Mono<MessageTo> put(
+ Chatroom chatroom,
+ String username,
+ Long messageId,
+ String text)
+ {