radiogroup.go
func (c *RadioGroup) SetSelected(id int) bool {
	found := false
	if id < 0 || id >= len(c.items) {
		return false
	}

	for idx, item := range c.items {
		if idx == id {
			found = true
			item.SetSelected(true)
		} else {
			item.SetSelected(false)
		}
	}

	return found
}
func (c *RadioGroup) SetSelected(id int) bool {
	found := false
	if id < 0 || id >= len(c.items) {
		return false
	}

	for idx, item := range c.items {
		if idx == id {
			found = true
			item.SetSelected(true)
		} else {
			item.SetSelected(false)
		}
	}

	return found
}
// SetSelected selects the radio by its number. The function
// returns false if the number is invalid for the radio group