@Test
public void throwErrorIfHeaderForPlaceholderIsMissing() {

    underTest.configure(mappingConfig, createMapperConfig(THING_TEMPLATE, COMMAND_HEADERS));
    final Map<String, String> missingEntityHeader = new HashMap<>();
    missingEntityHeader.put(HEADER_HONO_DEVICE_ID, DEVICE_ID);
    final ExternalMessage externalMessage =
            ExternalMessageFactory.newExternalMessageBuilder(missingEntityHeader).build();
    assertThatExceptionOfType(UnresolvedPlaceholderException.class)
            .isThrownBy(() -> underTest.map(externalMessage));
}