@Test(expected = ConnectException.class)
public void testBrokenKeyReplacementConfigurationNullValue() {

    final ByLogicalTableRouter<SourceRecord> subject = new ByLogicalTableRouter<>();
    final Map<String, String> props = new HashMap<>();
    props.put("topic.regex", "someValidRegex(.*)");
    props.put("topic.replacement", "$1");
    props.put("key.field.regex", "If this is set, key.field.replacement must be non-empty");
    subject.configure(props);
}