Is instance?
        Checks if provided object is instance of this service's model.

        :param model:           object
        :return:                bool

def is_instance(self, model):
        """
        Is instance?
        Checks if provided object is instance of this service's model.

        :param model:           object
        :return:                bool
        """
        result = isinstance(model, self.__model__)
        if result is True:
            return True

        err = 'Object {} is not of type {}'
        raise ValueError(err.format(model, self.__model__))