code: public static Method getValueOfStringMethod(Class<?> clazz) {
  		//System.err.println("clazz="+clazz);
  		Method existing = valueOfStringMethods.get(clazz);
  		if(existing==null) {
  			Method newMethod;
  			try {
  				newMethod = clazz.getMethod("valueOf", String.class);
  				int mod = newMethod.getModifiers();
  				if(!Modifier.isStatic(mod) || !Modifier.isPublic(mod)) newMethod = notExists;
  			} catch(NoSuchMethodException err) {
  				newMethod = notExists;
  			}
  			existing = valueOfStringMethods.put(clazz, newMethod);
  			if(existing==null) existing = newMethod;
  		}
  		return existing==notExists ? null : existing;
  	}
docs: Gets the <code>valueOf(String)</code> for the provided class or <code>null</code> if doesn't
  exist or is non-static or non-public.