Called on $save()
        Use modelform to save new object or modify an existing one

def ng_save(self, request, *args, **kwargs):
        """
        Called on $save()
        Use modelform to save new object or modify an existing one
        """
        form = self.get_form(self.get_form_class())
        if form.is_valid():
            obj = form.save()
            return self.build_json_response(obj)

        raise ValidationError(form.errors)