NullFeatures implements Features { public static NullFeatures newInstance() { return new NullFeatures(); } private  NullFeatures(); static NullFeatures newInstance(); @Override Optional<Feature> getFeature(final String featureId); @Override Features setFeature(final Feature feature); @Override @SuppressWarnings("squid:S4144") Features removeFeature(final String featureId); @Override Features setDefinition(final String featureId, final FeatureDefinition definition); @Override @SuppressWarnings("squid:S4144") Features removeDefinition(final String featureId); @Override Features setProperties(final String featureId, final FeatureProperties properties); @Override @SuppressWarnings("squid:S4144") Features removeProperties(final String featureId); @Override Features setProperty(final String featureId, final JsonPointer propertyPath, final JsonValue propertyValue); @Override Features removeProperty(final String featureId, final JsonPointer propertyPath); @Override boolean isNull(); @Override int getSize(); @Override boolean isEmpty(); @Override Stream<Feature> stream(); @Override Iterator<Feature> iterator(); @Override JsonObject toJson(final JsonSchemaVersion schemaVersion, final Predicate<JsonField> thePredicate); @Override int hashCode(); @Override boolean equals(final Object obj); @Override String toString();  }
@Test public void createInstanceReturnsTheExceptedJson() { final NullFeatures features = NullFeatures.newInstance(); assertThat(features.toJsonString()).isEqualTo("null"); }