code: protected static RedactableArgument logIdent(final Channel chan, final Endpoint endpoint) {
          String addr = chan != null ? chan.remoteAddress().toString() : endpoint.remoteAddress();
          return system("[" + addr + "][" + endpoint.getClass().getSimpleName() + "]: ");
      }
docs: Simple log helper to give logs a common prefix.
  
  @param chan the address.
  @param endpoint the endpoint.
  @return a prefix string for logs.