public static void chooseFiles(
    @NotNull FileChooserDescriptor descriptor,
    @Nullable Project project,
    @Nullable VirtualFile toSelect,
    @NotNull Consumer<? super List<VirtualFile>> callback
  ) {
    chooseFiles(descriptor, project, null, toSelect, callback);
  }
public static void chooseFiles(
    @NotNull FileChooserDescriptor descriptor,
    @Nullable Project project,
    @Nullable VirtualFile toSelect,
    @NotNull Consumer<? super List<VirtualFile>> callback
  )