Method IsDirectory

cpp/src/arrow/filesystem/gcsfs.cc:644–646

 private:
  static bool IsDirectory(const gcs::ObjectMetadata& o) {
    return o.has_metadata("arrow/gcsfs") && o.metadata("arrow/gcsfs") == "directory";
  }

  static Result<FileInfo> GetFileInfoBucket(const GcsPath& path,
                                            const google::cloud::Status& status) {