3 `type` declares a virtual types in a class. A bound type is
4 mandatory. Virtual types can then be used as regular types in the class
5 and its subclasses. Subclasses can also redefine it with a more specific
6 bound type. One can see a virtual type as an internal formal generic
7 parameter or as a redefinable *typedef*.
19 print b.derp + 1 # outputs 6