code: public static Features isAvailableOrThrowException(Features features, String feature, ClassLoader classLoader) {
        if (features == null) {
           features = new Features(classLoader);
        }
        isAvailableOrThrowException(features, feature);
        return features;
     }
docs: Verify that the specified feature is enabled. Initializes features if the provided one is null, allowing for
  lazily initialized Features instance.
  @param features existing instance or null.
  @param feature the feature string to check.
  @param classLoader to create the {@link Features} instance with if it doesn't already exist.
  @return the features instance that was checked, always non null
  @throws org.infinispan.commons.CacheConfigurationException thrown if the feature was disabled