public boolean isSet(_Fields field) {
    if (field == null) {
      throw new IllegalArgumentException();
    }

    switch (field) {
    case FILENAME:
      return isSetFilename();
    case CREATED:
      return isSetCreated();
    case UPDATED:
      return isSetUpdated();
    case DELETED:
      return isSetDeleted();
    case VERSION:
      return isSetVersion();
    case OWNER:
      return isSetOwner();
    case CONTENT_LENGTH:
      return isSetContentLength();
    case CONTENT_HASH:
      return isSetContentHash();
    }
    throw new IllegalStateException();
  }