Why is it simula don't realise they invented composition types & subtype not class or Mendel inheritance DNA/class?
Class is not a type or subtype.
Inheritance is not a sub or super part/class/type, or the building or implementing onsub or super part/class/type
Not any sub or supper type/class of child is your child only the one you put/ embed your DNA IS YOUR CHID FORMING DNA PARENT- CHILD RELATIONSHIPS.
Whereas with composition any components type/clsss/part will do, be it sub or super part/class/type so long as it fits and work whether they are or not DNA/ class related
Class is from the first part of biological evolutionarily theory ie Darwin classification of living organisms, 1800s papers.