### Question:
SpeedDetectorImpl extends SpeedDetector { @Override public Double detectSpeed(final List<? extends AbstractCarImage> images) { return ((double) images.size() / (double) FFMPEGVideoHandler.defaultFrameRate) * 3.6d * 10d; } private  SpeedDetectorImpl(); static SpeedDetectorImpl getInstance(); @Override String detect(final List<? extends AbstractCarImage> images); @Override Double detectSpeed(final List<? extends AbstractCarImage> images);  }### Answer:
@Test public void testDetectSpeed() { Double res = detector.detectSpeed(images); assertNotEquals(0d, res); Double expected = (images.size() / (double) FFMPEGVideoHandler.defaultFrameRate) * 3.6d * 10; assertEquals(res, detector.detectSpeed(images)); assertEquals(expected, res); }