toJson method

Implementation

Map toJson() {
  Map data = Map();
  data.putIfNotNull("fileId", _fileId);
  data.putIfNotNull("name", _fileName);
  data.putIfNotNull("owner", _fileOwner);
  data.putIfNotNull("createTime", _createTime);
  data.putIfNotNull("fileSize", _fileSize);
  return data;
}