public function functionAnnotations(string $function): array
    {
        $index = static::FUNCTION_CACHE . $function;

        return self::$annotations[$index]
            ?? self::$annotations[$index] = $this->setAnnotationValues(
                [
                    'function' => $function,
                ],
                ...$this->getReflectionFunctionAnnotations(
                $this->getFunctionReflection($function)
            )
            );
    }