code: public void write_u32(int w) throws IOException {
  		write_u8((w >> 24) & 0xFF);
  		write_u8((w >> 16) & 0xFF);
  		write_u8((w >> 8) & 0xFF);
  		write_u8(w & 0xFF);
  	}
docs: Write an unsigned integer value using 32bits using a big-endian encoding.
  
  @param w
  @throws IOException