code: public static List<IElement> getHeavyElements(IMolecularFormula formula) {
          List<IElement> newEle = new ArrayList<IElement>();
          for (IElement element : elements(formula)) {
              if (!element.getSymbol().equals("H")) {
                  newEle.add(element);
              }
          }
          return newEle;
      }
docs: Returns a set of nodes excluding all the hydrogens.
  
  @param   formula The IMolecularFormula
  @return          The heavyElements value into a List
  
  @cdk.keyword    hydrogen, removal