public function sanitize( $value = [] ) {
		if ( is_string( $value ) || is_numeric( $value ) ) {
			return [
				sanitize_text_field( $value ),
			];
		}
		$sanitized_value = [];
		foreach ( $value as $sub_value ) {
			if ( isset( $this->choices[ $sub_value ] ) ) {
				$sanitized_value[] = sanitize_text_field( $sub_value );
			}
		}
		return $sanitized_value;
	}