code: public static MonitorableRegistry getNamedInstance(String name) {
          MonitorableRegistry instance = NAMED_INSTANCES.get(name);
          if (instance == null) {
              instance = new MonitorableRegistry();
              MonitorableRegistry existing = NAMED_INSTANCES.putIfAbsent(name, instance);
              if (existing != null) {
                  return existing;
              }
          }
          return instance;
      }
docs: Retrieves or creates a centrally-accessible named instance, identified
  uniquely by the provided String. This is a convenience method to bridge
  between the old-style 'single registry' model (see
  {@link #DEFAULT_REGISTRY}) and having to pass a MonitorableRegistry down
  to the very depths of your class hierarchy. This is especially useful
  when instrumenting third-party code which cannot easily get access to a
  given MonitorableRegistry from a non-static context.
  
  @param name
  @return