private function addChildErrors (FormInterface $form, string $fieldPrefix, string $translationDomain, array &$allErrors) : void
    {
        foreach ($form->all() as $children)
        {
            $childErrors = $children->getErrors();
            $fieldName = \ltrim("{$fieldPrefix}{$children->getName()}");

            if (0 < \count($childErrors))
            {
                $allErrors[$fieldName] = \array_map(
                    function (FormError $error) use ($translationDomain)
                    {
                        return $this->translator->trans($error->getMessage(), [], $translationDomain);
                    },
                    \iterator_to_array($childErrors)
                );
            }

            $this->addChildErrors($children, "{$fieldName}_", $translationDomain, $allErrors);
        }
    }