### Question:
DateTimeFormatResolver extends TransformResolver { @Override public void init() { super.init(); customPattern = configuration .getStringPropertyValue(CUSTOM_PATTERN_KEY); LOGGER.info("Initialized [customPattern: {}]", customPattern); } DateTimeFormatResolver();  DateTimeFormatResolver(int priority); @Override Object transform(Object contextObject, String name,
            ResolutionContext context); @Override void init(); @Override Set<ConfigurationKey> getConfigurationKeys(); static final int DATE_TIME_FORMAT_RESOLVER_PRIORITY; static final ConfigurationKey CUSTOM_PATTERN_KEY; }### Answer:
@Test(expected = IllegalStateException.class) public void testMultipleInit() { DateTimeFormatResolver resolver = new DateTimeFormatResolver(); MustacheEngineBuilder.newBuilder() .omitServiceLoaderConfigurationExtensions() .addResolver(resolver).build(); resolver.init(null); }