code: public static double falsePositiveRate(long fpCount, long tnCount, double edgeCase) {
          //Edge case
          if (fpCount == 0 && tnCount == 0) {
              return edgeCase;
          }
          return fpCount / (double) (fpCount + tnCount);
      }
docs: Calculate the false positive rate from the false positive count and true negative count
  
  @param fpCount  False positive count
  @param tnCount  True negative count
  @param edgeCase Edge case values are used to avoid 0/0
  @return False positive rate