template.go
func (t *Template) Clone() *Template {
	t2 := &Template{
		Input:   t.Input,
		program: t.program,
	}
	return t2
}
func (t *Template) Clone() *Template {
	t2 := &Template{
		Input:   t.Input,
		program: t.program,
	}
	return t2
}
// Clone a template. This is useful for defining helpers on per "instance" of the template.