code: public OtpInputStream receiveBuf(final long timeout)
              throws InterruptedException, OtpErlangExit {
          final OtpMsg m = receiveMsg(timeout);
          if (m != null) {
              return m.getMsgBuf();
          }
  
          return null;
      }
docs: Wait for a message to arrive for this mailbox.
  
  @param timeout
  the time, in milliseconds, to wait for a message before
  returning null.
  
  @return a byte array representing the still-encoded body of the next
  message waiting in this mailbox.
  
  @exception OtpErlangExit
  if a linked {@link OtpErlangPid pid} has exited or has
  sent an exit signal to this mailbox.
  
  @exception InterruptedException
  if no message if the method times out before a message
  becomes available.