code: public static <E extends Enum<E>> EnumValidator<E> create(final Class<E> enumType, final EnumSet<E> allowed) {
          return new EnumValidator<E>(enumType, allowed);
      }
docs: Creates a new validator for the enum type with the allowed values defined in the {@code allowed} parameter.
  
  @param enumType the type of the enum.
  @param allowed  the enum values that are allowed.
  @param <E>      the type of the enum.
  
  @return a new validator.