'Load resource collections from the model. Each collection becomes
a :py:class:`~boto3.resources.collection.CollectionManager` instance
on the resource instance, which allows you to iterate and filter
through the collection\'s items.'

def _load_collections(self, attrs, resource_model, service_context):

    for collection_model in resource_model.collections:
        attrs[collection_model.name] = self._create_collection(resource_name=resource_model.name, collection_model=collection_model, service_context=service_context)
