code: public void reload() {
          providers.clear();
          lookupIterator = hasServicesDirectory()
              ? new LazyIterator(service, loader)
              : Collections.emptyIterator();
      }
docs: Clear this loader's provider cache so that all providers will be
  reloaded.
  
  <p> After invoking this method, subsequent invocations of the {@link
  #iterator() iterator} method will lazily look up and instantiate
  providers from scratch, just as is done by a newly-created loader.
  
  <p> This method is intended for use in situations in which new providers
  can be installed into a running Java virtual machine.