@Nullable
  public <P extends JpsElement> SourceFolder addSourceFolder(@NotNull final VirtualFile file, final JpsModuleSourceRootType<P> rootType,
                                                             final P properties) {
    final ContentEntry contentEntry = getContentEntry();
    if (contentEntry != null) {
      final SourceFolder sourceFolder = contentEntry.addSourceFolder(file, rootType, properties);
      myEventDispatcher.getMulticaster().sourceFolderAdded(this, sourceFolder);
      update();
      return sourceFolder;
    }

    return null;
  }
@Nullable
  public <P extends JpsElement> SourceFolder addSourceFolder(@NotNull final VirtualFile file, final JpsModuleSourceRootType<P> rootType,
                                                             final P properties)