According to official RSocket specifications: "A PAYLOAD MUST NOT have both (C)complete and (N)ext empty (false)", but rsocket-cpp does not comply with that statement when has to send fragmented frames. This behavior breaks cross-compatibility with the Java implementation (the one I'm trying to make it work with). ## Expected Behavior Since it is emitting an "item" because its invoked by (ChannelRequester::onNext) I think that at least the (N)ext flag should be set to true. ## Actual Behavior While the client actually fragments the payload correctly with the (F)ollows flag, it sets (C)complete and (N)ext to false. ## Steps to Reproduce * Modify the `channel-hello-world` example in order to send the content of a text file (bigger than 15MB) as Payload * Run the client against a server with fragmentation set to 15MB. ## Possible Solution Use the `addFlags` parameter of `rsocket::SreamsWriterImpl::writeFragmented` method to pass the right (N)ext and/or (C)omplete flags according to the Subscriber's method that has been invoked. ## Your Environment * RSocket version(s) used: 1.0 (specification), rsocket-cpp commit-id: 1fff6f82 * Other relevant libraries versions (eg. `netty`, ...): Spring Boot 2.3.3.RELEASE * Platform (eg. JVM version (`java -version`) or Node version (`node --version`)): Java 11.0.8 * OS and version (eg `uname -a`): Ubuntu 20.04