Inheritance vs composition

[mantielero]

With all this experiments with OOP, I have read in several places that Nim 
encourage composition against inheritance. I have read 
[this](https://medium.com/humans-create-software/composition-over-inheritance-cb6f88070205)
 which is very clear, but I don't know how this translates well into Nim. The 
inheritance is pretty clear to me, thanks to previous posts. It is more the 
composition bit.