code: public double getRecallForLabel(String label)
      {
          int fnAndTp = 0;
          double recall = 0;
          int tp = 0;
  
          if (map.containsKey(label) && map.get(label).containsKey(label)) {
              tp = this.map.get(label).get(label);
              fnAndTp = getRowSum(label);
          }
  
          if (fnAndTp > 0) {
              recall = (double) tp / (double) (fnAndTp);
          }
  
          return recall;
      }
docs: Return recall for single label
  
  @param label label
  @return double