def TrySnapshot(self):
    return (not self.op.remove_instance and
            self.instance.admin_state == constants.ADMINST_UP)
Does the FK or M2M table exist in the database already?
dataset/ETHPy150Open ganeti/ganeti/lib/cmdlib/backup.py/LUBackupExport.TrySnapshot--crossover with--dataset/ETHPy150Open callowayproject/django-categories/categories/migration.py/field_exists