private static String getMapKey(
      RawContactDelta entity, DataKind kind, ValuesDelta values, int viewIndex) {
    sWorkStringBuilder.setLength(0);
    if (entity != null) {
      sWorkStringBuilder.append(entity.getValues().getId());

      if (kind != null) {
        sWorkStringBuilder.append(KEY_SEPARATOR);
        sWorkStringBuilder.append(kind.mimeType);

        if (values != null) {
          sWorkStringBuilder.append(KEY_SEPARATOR);
          sWorkStringBuilder.append(values.getId());

          if (viewIndex != NO_VIEW_INDEX) {
            sWorkStringBuilder.append(KEY_SEPARATOR);
            sWorkStringBuilder.append(viewIndex);
          }
        }
      }
    }
    return sWorkStringBuilder.toString();
  }