private static @NotNull String findBlob(@NotNull Map<Pair<GitRevisionNumber, FilePath>, String> blobs,
                                          @NotNull ContentRevision revision) throws VcsException {
    FilePath filePath = revision.getFile();
    GitRevisionNumber number = (GitRevisionNumber)revision.getRevisionNumber();
    String blob = blobs.get(Pair.create(number, filePath));
    if (blob == null) throw new VcsException(GitBundle.message("blob.not.found", number, filePath));
    return blob;
  }
private static @NotNull String findBlob(@NotNull Map<Pair<GitRevisionNumber, FilePath>, String> blobs,
                                          @NotNull ContentRevision revision)