'G', 'kg' => 'KG', 'ton' => 'T', ]; } protected static function labels(): array { return [ 'g' => __('Gramme'), 'kg' => __('Kg'), 'ton' => __('Tonne'), ]; } public static function convert(): array { return [ 'G' => 0.001, 'KG' => 1, 'T' => 1000, ]; } public function __toString(): string { return (string)$this->label; } }