@NotNull
  public static BackgroundableActionLock getHistoryLock(@NotNull AbstractVcs vcs,
                                                        @NotNull VcsBackgroundableActions actionKey,
                                                        @NotNull FilePath filePath,
                                                        @Nullable VcsRevisionNumber startRevisionNumber) {
    if (startRevisionNumber != null) {
      return getLock(vcs.getProject(), actionKey, filePath.getPath(), startRevisionNumber.asString());
    }
    return getLock(vcs.getProject(), actionKey, filePath.getPath());
  }
@NotNull
  public static BackgroundableActionLock getHistoryLock(@NotNull AbstractVcs vcs,
                                                        @NotNull VcsBackgroundableActions actionKey,
                                                        @NotNull FilePath filePath,
                                                        @Nullable VcsRevisionNumber startRevisionNumber)