Better way for adding custom serializers

[berislavlopac]

At the moment, I managed to add custom mimetype serializers by patching the MEDIA_TYPE_DESERIALIZERS dict, like this:

from openapi_core.schema.media_types.models import MEDIA_TYPE_DESERIALIZERS
import json

MEDIA_TYPE_DESERIALIZERS['application/my.api+json'] = json.loads

Am I missing a better way to do it, e.g. by passing it to the validator constructor or something? Thank you!