BreadcrumbBuilderInterface

Drupal 8 print current breadcrumb trail with route title

Whao, that wasn't as easy as I thought. I wanted to print out the two top level breadcrumb elements, without "Home", with node title in a custom block. I tried it in many different ways but ran into surprises every time. So finally I'd like to share my code with you, if you should run into the same situation: