@classmethod
def blend(cls, model, **params):
    """ Get a mixer class for model.

        :return instance:

        """
    scheme = cls.__load_cls(model)
    backend = cls.__store__.get(scheme)
    if not backend:
        if cls.__is_django_model(scheme):
            from .backend.django import mixer as backend
        elif cls.__is_sqlalchemy_model(scheme):
            from .backend.sqlalchemy import mixer as backend
        elif cls.__is_mongoengine_model(scheme):
            from .backend.mongoengine import mixer as backend
        cls.__store__[scheme] = backend
    return backend.blend(scheme, **params)
