Should we limit request-response to a single protocol?

[dariusc93]

Going over request-response protocol, I began looking closely at its support for multiple protocols, however I could not find any use-case for supporting multiple protocols while being unable to explicitly send a request over a specific protocol itself, unless there is something I am overlooking (which is possible too). In this case, should we limit it to support a single protocol?

[drHuangMHT]

I don't see how request-response handles multiple protocols because codec::Protocol is AsRef<str>, which I don't believe there is any way of switching between different protocols after reading the code. So yeah we can limit it but it only supports one protocol anyway, we may just need to change the documentation.