

def _do_checks(self, block, exists):
    interesting = ['compute.instance.rebuild.end', 'compute.instance.finish_resize.end', 'compute.instance.rescue.end']
    self._confirm_launched_at(block, exists)
    fields = self._get_core_fields()
    last_interesting = None
    for event in block:
        if (event['event_type'] in interesting):
            last_interesting = exists
    if last_interesting:
        self._verify_fields(last_interesting, exists, fields)
    elif self._is_non_EOD_exists(exists):
        self.warnings.append(('Non-EOD .exists found (msg_id: %s) with no operation event.' % exists['message_id']))
    deleted = self._find_deleted_events(block)
    delete_fields = ['launched_at', 'deleted_at']
    self._confirm_delete(exists, deleted, delete_fields)

dataset/ETHPy150Open openstack/stacktach-winchester/winchester/pipeline_handler.py UsageHandler._do_checks/VarMisuse@66/117 `event`->`exists`