func DoubleErrorPanic() {
	panic(examplePanicError{})
}

type exampleStringer struct{}

func (s exampleStringer) String() string {
	panic("important multi-line\nstringer message")
}

func StringerPanic() {
	panic(exampleStringer{})
}

type examplePanicStringer struct{}

func (s examplePanicStringer) String() string {
	panic(exampleStringer{})
}

func DoubleStringerPanic() {

type Animal struct {
	Name string
	Age  uint
}

// String makes Animal satisfy the Stringer interface.
func (a Animal) String() string {
	return fmt.Sprintf("%v (%d)", a.Name, a.Age)
}

func ExampleStringer() {
	a := Animal{
		Name: "Gopher",
		Age:  2,
	}
	fmt.Println(a)
	// Output: Gopher (2)