@Test
public void tryToRemoveMandatoryHeader() {

    final SoftAssertions softly = new SoftAssertions();
    for(MessageHeaderDefinition mandatoryHeaderDefinition : MessageHeadersBuilder.MANDATORY_HEADERS) {
        final String key = mandatoryHeaderDefinition.getKey();
        softly.assertThatThrownBy(() -> underTest.removeHeader(key))
                .isInstanceOf(IllegalArgumentException.class)
                .withFailMessage("Mandatory header with key <%s> cannot be removed!", key)
                .hasNoCause();
    }
    softly.assertAll();
}