def METHOD_NAME(self, attrs: dict[str, Any]) -> dict[str, Any]:
    """Check that only a single source has password_sync on"""
    sync_users_password = attrs.get("sync_users_password", True)
    if sync_users_password:
        sources = LDAPSource.objects.filter(sync_users_password=True)
        if self.instance:
            sources = sources.exclude(pk=self.instance.pk)
        if sources.exists():
            raise ValidationError(
                {
                    "sync_users_password": (
                        "Only a single LDAP Source with password synchronization is allowed"
                    )
                }
            )
    return super().METHOD_NAME(attrs)