code: protected Stringifier<String> registerStringStringifier(Stringifier nullStringifier) {
  		Stringifier<String> stringStringifier = new BaseStringifier<String>(nullStringifier) {
  			@Override
  			protected String doToString(String s) {
  				return s;
  			}
  		};
  		compositeStringifier.add(String.class, stringStringifier);
  		return stringStringifier;
  	}
docs: Register a stringifier for String values.
  Method aimed at being overridden.