message: Add comment of Connection
diff: @@ -43,6 +43,9 @@ impl error::Error for Error {
  type Result<T> = result::Result<T, Error>;
  +/// The "Heavy" connection owning the full control of the network-transport-tcp stream.
  +///
  +/// This is where the basic multiplexing is done, and where command (open/close light connection) are handled.
  pub struct Connection<W: Sized> {
  stream: W,
  drg: u64,
  