code: private double calculateMassT(List<IIsotope> isoToCond_new, int[] value_In) {
          double result = 0;
          for (int i = 0; i < isoToCond_new.size(); i++) {
              if (value_In[i] != 0) {
                  result += isoToCond_new.get(i).getExactMass() * value_In[i];
              }
          }
          return result;
      }
docs: Calculate the mass total given the elements and their respective occurrences.
  
  @param elemToCond_new  The IIsotope to calculate
  @param value_In        Array matrix with occurrences
  @return                The sum total