@Test
public void inputContainsNestedLegacyPlaceholderThrowsException() {

    final String nestedPlaceholder = "${" + LEGACY_REPLACER + "}";
    assertThatExceptionOfType(GatewayPlaceholderNotResolvableException.class)
            .isThrownBy(() -> underTest.substitute(nestedPlaceholder, DITTO_HEADERS));
}