code: private static final int compareInt64AsUnsigned(long a, long b) {
          a += 0x8000000000000000L;
          b += 0x8000000000000000L;
          if(a < b) {
              return -1;
          } else if(a > b) {
              return 1;
          } else {
              return 0;
          }
      }
docs: Compare two signed long values as if they were unsigned.