Untitled

type
    Base = ref object of RootObj
    A = ref object of Base
    B = ref object of Base

method inner(obj: Base) {.base.} =
    quit "to override"


method outer(obj: Base) {.base.} =
    echo "outer"
    obj.inner()


method inner(a: A) =
    echo "inner A"


method inner(b: B) =
    echo "inner B"


var a: A
var b: B

a.outer()
b.outer()