code: public void sendInteger4(int val) throws IOException {
      int4Buf[0] = (byte) (val >>> 24);
      int4Buf[1] = (byte) (val >>> 16);
      int4Buf[2] = (byte) (val >>> 8);
      int4Buf[3] = (byte) (val);
      pgOutput.write(int4Buf);
    }
docs: Sends a 4-byte integer to the back end.
  
  @param val the integer to be sent
  @throws IOException if an I/O error occurs