Return the default value to use when validating data if no input
        is provided for this field.

        If a default has not been set for this field then this will simply
        return `empty`, indicating that no value should be set in the
        validated data for this field.

def get_default(self):
        """
        Return the default value to use when validating data if no input
        is provided for this field.

        If a default has not been set for this field then this will simply
        return `empty`, indicating that no value should be set in the
        validated data for this field.
        """
        if self.default is empty:
            raise SkipField()
        if callable(self.default):
            if hasattr(self.default, 'set_context'):
                self.default.set_context(self)
            return self.default()
        return self.default