docs: public <P extends Plugin> Iterator<P> load(Class<P> service) {
  		ArrayList<Iterator<P>> combinedIterators = new ArrayList<>(pluginDescriptors.size());
  		for (PluginDescriptor pluginDescriptor : pluginDescriptors) {
  			PluginLoader pluginLoader = new PluginLoader(pluginDescriptor, parentClassLoader);
  			combinedIterators.add(pluginLoader.load(service));
  		}
  		return Iterators.concat(combinedIterators.iterator());
  	}