pub fn create_postcard_streams<S, D>(
recv: RecvStream,
send: SendStream,
) -> (Framed<FramedRead<RecvStream, LengthDelimitedCodec>, S, S, PostcardFormat>, Framed<FramedWrite<SendStream, LengthDelimitedCodec>, D, D, PostcardFormat>)pub fn create_postcard_streams<S, D>(
recv: RecvStream,
send: SendStream,
) -> (Framed<FramedRead<RecvStream, LengthDelimitedCodec>, S, S, PostcardFormat>, Framed<FramedWrite<SendStream, LengthDelimitedCodec>, D, D, PostcardFormat>)