private @NotNull <T> Collection<T> loadExtensions(@NotNull Class<T> extensionClass, @Nullable Predicate<? super PluginDescriptor> filter) {
    Set<ClassLoader> loaders = new LinkedHashSet<>();
    for (PluginDescriptor plugin : myExternalBuildPlugins) {
      if (filter == null || filter.test(plugin)) {
        ContainerUtil.addIfNotNull(loaders, plugin.getPluginClassLoader());
      }
    }
    if (loaders.isEmpty()) {
      loaders.add(getClass().getClassLoader());
    }
    return loadExtensionsFrom(loaders, extensionClass);
  }
private @NotNull <T> Collection<T> loadExtensions(@NotNull Class<T> extensionClass, @Nullable Predicate<? super PluginDescriptor> filter)