Real Go Projects: SmartTwitter and web.go(blog.golang.org)

  type Foo interface {
  	Bar()
  	Baz() string
  }
  
  type Something struct {
  	// ...
  }
  
  func (s *Something) Bar() {
  	// ...
  }
  
  func (s *Something) Baz() string {
  	// ...
        return "a string"
  }
  
  func DoFoo(foo Foo) {
 	// ...
  }
  
  func main() {
        f := new(Something)
  
        DoFoo(f)
  }