code: public ImmutableList<Class<?>> getClassObjects(final String param) {
      final ImmutableList.Builder<Class<?>> ret = ImmutableList.builder();
      for (final String className : getStringList(param)) {
        try {
          ret.add(getClassObjectForString(className));
        } catch (ClassNotFoundException e) {
          throw new ParameterConversionException(fullString(param), className, e, "class");
        }
      }
      return ret.build();
    }
docs: Turns a parameter whose value is a comma-separated list of class names into a list of the
  corresponding {@link Class} objects.