In one of my apps i have a NSOperationQueue and some subclass of NSOperations.
I've added some dependencies so, the operation A not start until operation B finish.

I need to cancel the operation A if the operation B fails, but from inside the operation B i don't have any list of operation who dependes on the current operation.

I will try to add some weak properties on my subclass, like

`@property (nonatomic, weak) NSArray *dependsOnMe;`

but i'm afraid to generate some strange loop.

thanks