code: function bi_flush() {
        if (bi_valid == 16) {
          put_short(bi_buf);
          bi_buf = 0;
          bi_valid = 0;
        } else if (bi_valid >= 8) {
          put_byte(bi_buf & 0xff);
          bi_buf >>>= 8;
          bi_valid -= 8;
        }
      }
docs: Flush the bit buffer, keeping at most 7 bits in it.