static boolean lessThanUnsigned(long x1,long x2){
  return (x1 + Long.MIN_VALUE) < (x2 + Long.MIN_VALUE);
}

static boolean lessThanUnsigned ( long x1 , long x2 ) { return ( x1 + Long . MIN_VALUE ) < ( x2 + Long . MIN_VALUE ) ; }
returns true if x1 is less than x2 , when both values are treated as unsigned .
