code: @Override
    public String getDefaultManagerName(ClassLoader cl) {
      ConfigurationContext ctx = classLoader2config.get(cl);
      if (ctx == null) {
        ctx = createContext(cl, null, DEFAULT_CONFIGURATION_FILE);
        Map<ClassLoader, ConfigurationContext> m2 = new HashMap<ClassLoader, ConfigurationContext>(classLoader2config);
        m2.put(cl, ctx);
        classLoader2config = m2;
      }
      return ctx.getManagerConfiguration().getDefaultManagerName();
    }
docs: The name of the default manager may be changed in the configuration file.
  Load the default configuration file and save the loaded context for the respective
  classloader, so we do not load the context twice when we create the first cache.