code: public static List<IQProvider<IQ>> getIQProviders() {
          List<IQProvider<IQ>> providers = new ArrayList<>(iqProviders.size());
          providers.addAll(iqProviders.values());
          return providers;
      }
docs: Returns an unmodifiable collection of all IQProvider instances. Each object
  in the collection will either be an IQProvider instance, or a Class object
  that implements the IQProvider interface.
  
  @return all IQProvider instances.