### Question:
InMemoryCache { public void removeFeature(String id) { features.remove(id); } @Inject  InMemoryCache(); synchronized void putFeature(Feature feature); void removeFeature(String id); synchronized ImmutableSet<Feature> getFeatures(); void clear(); Optional<Feature> getFeature(String featureId);  }### Answer:
@Test public void removeFeature() { inMemoryCache.putFeature(FAKE_FEATURE); inMemoryCache.removeFeature(FAKE_FEATURE.getId()); assertThat(inMemoryCache.getFeatures()).isEmpty(); }