public static void processVirtualFilesByVcs(@NotNull Project project,
                                              @NotNull Collection<? extends VirtualFile> files,
                                              @NotNull PerVcsProcessor<VirtualFile> processor) {
    if (files.isEmpty()) {
      return;
    }

    ProjectLevelVcsManager projectLevelVcsManager = ProjectLevelVcsManager.getInstance(project);
    processItemsByVcs(files, file -> projectLevelVcsManager.getVcsFor(file), processor);
  }
public static void processVirtualFilesByVcs(@NotNull Project project,
                                              @NotNull Collection<? extends VirtualFile> files,
                                              @NotNull PerVcsProcessor<VirtualFile> processor)