private function removeUseFunctionsFromBackslashing(FileGenerator $generator, array $functions)
    {
        foreach ($generator->getUses() as $namespacedFunction) {
            list($functionOrClass) = $namespacedFunction;

            if (\function_exists($functionOrClass)) {
                $function = \explode("\\", $functionOrClass);
                $function = \array_pop($function);

                if (!empty($functions[$function])) {
                    unset($functions[$function]);
                }
            }
        }

        return $functions;
    }