public function mergeInclude(array $data, array $includeData): array
    {
        foreach ($data as $class => $fixtures) {
            // $class is either a FQCN or 'parameters'
            $includeData[$class] = (
                    array_key_exists($class, $includeData)
                    && is_array($includeData[$class])
                    && is_array($fixtures)
                )
                ? array_merge($includeData[$class], $fixtures)
                : $fixtures
            ;
        }

        return $includeData;
    }