public static @Nullable StagedFile listTree(@NotNull GitRepository repository,
                                              @NotNull FilePath filePath,
                                              @NotNull VcsRevisionNumber revision) throws VcsException {
    List<StagedFileOrDirectory> result = listTree(repository, Collections.singleton(filePath), revision);
    if (result.size() != 1 || !(result.get(0) instanceof StagedFile)) return null;
    return (StagedFile)result.get(0);
  }
public static @Nullable StagedFile listTree(@NotNull GitRepository repository,
                                              @NotNull FilePath filePath,
                                              @NotNull VcsRevisionNumber revision)