class ChangePasswordFormType extends AbstractType
{
    /**
     * @var TranslatorInterface
     */
    private $translator;

    public function __construct(TranslatorInterface $translator)
    {
        $this->translator = $translator;
    }

    /**
     * @param mixed[]                                           $options
     * @param FormBuilderInterface<FormBuilderInterface|string> $builder
     */
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $message = $this->translator->trans('This is the string I would like to translate', $parameters = [], $domain = 'validators');

        // other code...
    }
}