There is no "serializer" service

Docs says:

This bundle registers a normalizer to serialize forms with errors into an array.

$serializer = $this->get('serializer');
$initialValues = $serializer->normalize($form);

but there is no "serializer" service registered. I see in services.yml that there is InitialValuesNormalizer

<service id="liform.serializer.initial_values_normalizer" class="Limenius\Liform\Serializer\Normalizer\InitialValuesNormalizer" public="false">
  <tag name="serializer.normalizer" priority="-10" />
</service>

but it is public="false" so I can't access it.

I have eneded with this:

$normalizer = new \Limenius\Liform\Serializer\Normalizer\InitialValuesNormalizer();
$initialValues = $normalizer->normalize($form);

Limenius / LiformBundle

There is no "serializer" service #14