code: public static AbstractConfiguration getConfigInstance() {
          if (instance == null) {
              synchronized (ConfigurationManager.class) {
                  if (instance == null) {
                      instance = getConfigInstance(Boolean.getBoolean(DynamicPropertyFactory.DISABLE_DEFAULT_CONFIG));
                  }
              }
          }
          return instance;
      }
docs: Get the current system wide configuration. If there has not been set, it will return a default
  {@link ConcurrentCompositeConfiguration} which contains a SystemConfiguration from Apache Commons
  Configuration and a {@link DynamicURLConfiguration}.