### Question:
FlickrPhotosExporter implements Exporter<AuthData, PhotosContainerResource> { @VisibleForTesting static String toMimeType(String flickrFormat) { switch (flickrFormat) { case "jpg": case "jpeg": return "image/jpeg"; case "png": return "image/png"; case "gif": return "image/gif"; default: throw new IllegalArgumentException("Don't know how to map: " + flickrFormat); } } FlickrPhotosExporter(AppCredentials appCredentials, TransferServiceConfig serviceConfig); @VisibleForTesting  FlickrPhotosExporter(Flickr flickr, TransferServiceConfig serviceConfig); @Override ExportResult<PhotosContainerResource> export(
      UUID jobId, AuthData authData, Optional<ExportInformation> exportInformation);  }### Answer:
@Test public void getMimeType() { assertThat(FlickrPhotosExporter.toMimeType("jpeg")).isEqualTo("image/jpeg"); assertThat(FlickrPhotosExporter.toMimeType("gif")).isEqualTo("image/gif"); }