### Question:
ReflectionResolver extends AbstractResolver { @Override public void init() { long memberCacheMaxSize = configuration .getLongPropertyValue(MEMBER_CACHE_MAX_SIZE_KEY); LOGGER.debug("Initialized [memberCacheMaxSize: {}]", memberCacheMaxSize); if (memberCacheMaxSize > 0) { memberCache = configuration.getComputingCacheFactory().create( COMPUTING_CACHE_CONSUMER_ID, ReflectionResolver::findWrapper, null, memberCacheMaxSize, null); } hintFallbackEnabled = configuration .getBooleanPropertyValue(HINT_FALLBACK_ENABLED_KEY); } ReflectionResolver();  ReflectionResolver(int priority); @Override Object resolve(Object contextObject, String name,
            ResolutionContext context); @Override Hint createHint(Object contextObject, String name,
            ResolutionContext context); @Override void init(); @Override Set<ConfigurationKey> getConfigurationKeys(); void invalidateMemberCache(Predicate<Class<?>> predicate); static final int REFLECTION_RESOLVER_PRIORITY; static final String COMPUTING_CACHE_CONSUMER_ID; static final ConfigurationKey MEMBER_CACHE_MAX_SIZE_KEY; static final ConfigurationKey HINT_FALLBACK_ENABLED_KEY; static final String GET_PREFIX; static final String IS_PREFIX; }### Answer:
@Test(expected = IllegalStateException.class) public void testMultipleInit() { ReflectionResolver resolver = new ReflectionResolver(); MustacheEngineBuilder.newBuilder().omitServiceLoaderConfigurationExtensions().addResolver(resolver).build(); resolver.init(null); }