@NotNull
  public static List<VcsDirectoryMapping> addMapping(@NotNull List<? extends VcsDirectoryMapping> existingMappings,
                                                     @NotNull @NonNls String path,
                                                     @NotNull @NonNls String vcs) {
    return addMapping(existingMappings, new VcsDirectoryMapping(path, vcs));
  }
@NotNull
  public static List<VcsDirectoryMapping> addMapping(@NotNull List<? extends VcsDirectoryMapping> existingMappings,
                                                     @NotNull @NonNls String path,
                                                     @NotNull @NonNls String vcs)