public function setType(?string $type): self
    {
        if (!$this->isValidType($type)) {
            throw new \InvalidArgumentException(\sprintf(
                "Invalid type '%s'. Must be either NULL, one of %s, or a fully qualified class name or interface",
                $type,
                \implode(', ', $this->getValidTypes())
            ));
        }

        $this->type = $type;

        return $this;
    }