@Test
public void tryToGetInstanceWithUnknownQueryParametersAsHeaders() {

    final List<String> unknownHeaderKeys = Lists.newArrayList("foo", "bar");
    final List<String> knownHeaderKeys = Lists.newArrayList(DittoHeaderDefinition.CORRELATION_ID.getKey(),
            DittoHeaderDefinition.RESPONSE_REQUIRED.getKey());
    final List<String> allHeaderKeys = new ArrayList<>(knownHeaderKeys);
    allHeaderKeys.addAll(unknownHeaderKeys);
    final String configPath = "http." + HttpConfig.GatewayHttpConfigValue.QUERY_PARAMS_AS_HEADERS.getConfigPath();
    final Config config = ConfigFactory.parseMap(Maps.newHashMap(configPath, allHeaderKeys));
    assertThatExceptionOfType(DittoConfigError.class)
            .isThrownBy(() -> GatewayHttpConfig.of(config))
            .withMessage("The query parameter names <%s> do not denote known header keys!", unknownHeaderKeys)
            .withNoCause();
}