def clean_custom_chat_template(self):
        if not self._cchq_is_previewer:
            return None
        value = self._clean_dependent_field("use_custom_chat_template",
            "custom_chat_template")
        if value is not None and settings.CUSTOM_CHAT_TEMPLATES not in value:
            raise ValidationError(_("Unknown custom template identifier."))
        return value
dataset/ETHPy150Open dimagi/commcare-hq/corehq/apps/sms/forms.py/SettingsForm.clean_custom_chat_template/swapped operands of `not in`