@Test
public void fromDittoHeaders() {

    final DittoHeaders dittoHeaders =
            DittoHeaders.newBuilder().ifNoneMatch(EntityTagMatchers.fromCommaSeparatedString("*")).build();
    final Optional<IfNoneMatchPreconditionHeader> ifNoneMatchPreconditionHeader =
            IfNoneMatchPreconditionHeader.fromDittoHeaders(dittoHeaders);
    Assertions.assertThat(ifNoneMatchPreconditionHeader).isPresent();
    assertThat(ifNoneMatchPreconditionHeader.get().getKey()).isEqualTo("if-none-match");
    assertThat(ifNoneMatchPreconditionHeader.get().getValue()).isEqualTo("*");
}