Symfony\Component\Serializer\Normalizer\AbstractNormalizer::setCallbacks PHP Method

    public function setCallbacks(array $callbacks)
    {
        foreach ($callbacks as $attribute => $callback) {
            if (!is_callable($callback)) {
                throw new InvalidArgumentException(sprintf('The given callback for attribute "%s" is not callable.', $attribute));
            }
        }
        $this->callbacks = $callbacks;
        return $this;
    }