[WIP] poc/apiimport2.0

isn't weird to have : 
public function setSerializer(SerializerInterface $serializer)
{
if (!$serializer instanceof NormalizerInterface) {
       throw new \LogicException('Serializer must be a normalizer');
}
   $this->serializer = $serializer;
}

You typehint for a SerializerInteface and then you ask for a NormalizerInterface ?