@Nullable
  private String readPreviousTestRunId() {
    try {
      BufferedReader reader =
          new BufferedReader(new FileReader(new File(mDir, SCREENSHOT_TESTS_RUN_ID_FILE_NAME)));
      return reader.readLine();
    } catch (IOException e) {
      return null;
    }
  }
Creates a "local" album that stores all the images on device.
core/src/main/java/com/facebook/testing/screenshot/internal/AlbumImpl.java