@Nullable
  private Library createLibrary(final ModifiableRootModel rootModel, @Nullable LibrariesContainer additionalContainer) {
    if (myNewLibraryEditor != null) {
      return LibrariesContainerFactory.createLibrary(additionalContainer, LibrariesContainerFactory.createContainer(rootModel),
                                                     myNewLibraryEditor, getLibraryLevel());
    }
    return null;
  }
@Nullable
  private Library createLibrary(final ModifiableRootModel rootModel, @Nullable LibrariesContainer additionalContainer)