@Test
public void invalidBooleanStringValue() {

    Mockito.when(headerDefinition.getJavaType()).thenReturn(Boolean.class);
    final String value = "foo";
    assertThatExceptionOfType(DittoHeaderInvalidException.class)
            .isThrownBy(() -> underTest.accept(headerDefinition, value))
            .withMessage("The value '%s' of the header '%s' is not a valid boolean.", value, HEADER_KEY)
            .withNoCause();
}