@Nullable
  public LibraryCompositionSettings apply() {
    if (mySettings == null) return null;

    final Choice option = myButtonEnumModel.getSelected();
    mySettings.setDownloadLibraries(option == Choice.DOWNLOAD);

    final Object item = myExistingLibraryComboBox.getSelectedItem();
    if (option == Choice.USE_LIBRARY && item instanceof ExistingLibraryEditor) {
      mySettings.setSelectedExistingLibrary(((ExistingLibraryEditor)item).getLibrary());
    }
    else {
      mySettings.setSelectedExistingLibrary(null);
    }

    if (option == Choice.USE_LIBRARY && item instanceof NewLibraryEditor) {
      mySettings.setNewLibraryEditor((NewLibraryEditor)item);
    }
    else {
      mySettings.setNewLibraryEditor(null);
    }

    mySettings.setLibraryProvider(option == Choice.USE_FROM_PROVIDER ? myLibraryProvider : null);
    return mySettings;
  }
@Nullable
  public LibraryCompositionSettings apply()