code: public static boolean containsElement(IMolecularFormula formula, IElement element) {
  
          for (IIsotope isotope : formula.isotopes()) {
              if (element.getSymbol().equals(isotope.getSymbol())) return true;
          }
  
          return false;
      }
docs: True, if the MolecularFormula contains the given element as IIsotope object.
  
  @param  formula   IMolecularFormula molecularFormula
  @param  element   The element this MolecularFormula is searched for
  @return           True, if the MolecularFormula contains the given element object