Playing with this post: http://xampl.com/so/2012/06/27/followup-to-a-rubyist-has-some-difficulties-with-go-limits-to-polymorphism-and-method-dispatch-in-go/

interfaces_overrides.go

package main

import "fmt"

type Doer interface {
	Do(i int)
}
type Base struct{}

func (b Base) Do(i int) {
	fmt.Printf("Doer number: %d  Base did something.\n", i + 1)
}

type SubSimple struct {
	Base
}
type SubComplex struct {
	Base
}

func (s SubComplex) Do(i int) {
	fmt.Println("Preparing for Base doing.")
	s.Base.Do(i)
	fmt.Println("Tear down after Base did.")
}
func main() {
	var doers []Doer = []Doer{*new(Base), *new(SubSimple), *new(SubComplex)}
	for offset, doer := range doers {
		doer.Do(offset)
	}
}

/*
Doer number: 1  Base did something.
Doer number: 2  Base did something.
Preparing for Base doing.
Doer number: 3  Base did something.
Tear down after Base did.
*/