selectable.go
func (s *selectable) FindByButton(text string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.Button, text).Single())
}
func (s *selectable) FindByButton(text string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.Button, text).Single())
}
// FindByButton finds exactly one button element with the provided text.
// Supports <button>, <input type="button">, and <input type="submit">.