Init model with field.

        :param DomainModel model:
        :param object value:

def init_model(self, model, value):
        """Init model with field.

        :param DomainModel model:
        :param object value:
        """
        if value is None and self.default is not None:
            value = self.default() if callable(self.default) else self.default

        self.set_value(model, value)