resolvePlaceholderValue example

        return $this->name;
    }

    final public function merge(mixed $leftSide, mixed $rightSide): mixed
    {
        if (!$this->allowOverwrite) {
            throw new ForbiddenOverwriteException(sprintf('Configuration path "%s" cannot be overwritten. You have to define all options for this path, and any of its sub-paths in one configuration section.', $this->getPath()));
        }

        if ($leftSide !== $leftPlaceholders = self::resolvePlaceholderValue($leftSide)) {
            foreach ($leftPlaceholders as $leftPlaceholder) {
                $this->handlingPlaceholder = $leftSide;
                try {
                    $this->merge($leftPlaceholder, $rightSide);
                } finally {
                    $this->handlingPlaceholder = null;
                }
            }

            return $rightSide;
        }