agent/eventhandler/task_handler.go
func (handler *TaskHandler) batchContainerEventUnsafe(event api.ContainerStateChange) {
	seelog.Infof("TaskHandler: batching container event: %s", event.String())
	handler.tasksToContainerStates[event.TaskArn] = append(handler.tasksToContainerStates[event.TaskArn], event)
}
func (handler *TaskHandler) batchContainerEventUnsafe(event api.ContainerStateChange) {
	seelog.Infof("TaskHandler: batching container event: %s", event.String())
	handler.tasksToContainerStates[event.TaskArn] = append(handler.tasksToContainerStates[event.TaskArn], event)
}
// batchContainerEventUnsafe collects container state change events for a given task arn