code: public static String getString(IMolecularFormula formula, String[] orderElements,
                                     boolean setOne) {
          return getString(formula, orderElements, setOne, true);
      }
docs: Returns the string representation of the molecular formula.
  
  @param formula       The IMolecularFormula Object
  @param orderElements The order of Elements
  @param setOne        True, when must be set the value 1 for elements with
  one atom
  @return A String containing the molecular formula
  @see #getHTML(IMolecularFormula)
  @see #generateOrderEle()
  @see #generateOrderEle_Hill_NoCarbons()
  @see #generateOrderEle_Hill_WithCarbons()