code: public <T> ClassController<T> on(final Class<T> clazz) {
  		return new DefaultClassController<T>(provider, clazz);
  	}
docs: Method to access reflection on clazz.
  
  @param clazz
  Class object to be used.
  @return A object that allows you to access reflection on class clazz.
  @throws IllegalArgumentException
  if clazz is null.