public function contextServiceId(string $serviceId, string $context = null, string $member = null): string
    {
        $index = $serviceId . '@' . ($context ?? '');

        // If there is a method
        if (null !== $member) {
            // If there is a class
            if (null !== $context) {
                // Add the double colon to separate the method name and class
                $index .= '::';
            }

            // Append the method/function to the string
            $index .= $member;
        }

        // service@class
        // service@method
        // service@class::method
        return $index;
    }