protected function checkbox($name, $label = null, $value = null, $note = null) {
		$data = is_array($value) ? $value + ['note' => $note] : (
			is_bool($value)
			? ['checked' => $value, 'note' => $note]
			: ['note' => $value]
		);
		return $this->field($name, Checkbox::class, $label, [
			'checked' => Checkbox::b($this->v($name), df_bool(dfa($data, 'checked')))
		] + $data);
	}