def METHOD_NAME(self, data):
    webhook = self.instance
    # If webhook is being copied instance won't exist to copy values from
    if not webhook and "id" in data:
        webhook = Webhook.objects.get(
            public_primary_key=data["id"], organization=self.context["request"].auth.organization
        )
    if data.get("password") == WEBHOOK_FIELD_PLACEHOLDER:
        data["password"] = webhook.password
    if data.get("authorization_header") == WEBHOOK_FIELD_PLACEHOLDER:
        data["authorization_header"] = webhook.authorization_header
    return super().METHOD_NAME(data)