@Test
  public void testOutMimeType() throws Throwable {
    BitmapFactory.Options options = new BitmapFactory.Options();

    // NULLSAFE_FIXME[Not Vetted Third-Party]
    if (options.outMimeType != null) {
      // Not all devices are able to get this info from the image
      assertEquals("Mime type should be detected properly", "image/webp", options.outMimeType);
    }

    WebpBitmapFactoryImpl.hookDecodeStream(getTestJpegInputStream(), null, options);
    assertEquals("Mime type should be detected properly", "image/jpeg", options.outMimeType);
  }
Return input stream for lossless webp

@return InputStream instance
static-webp/src/androidTest/java/com/facebook/webpsupport/WebpBitmapFactoryTest.java