         _internalErrors += errors
         cancel()
     }
-
-    // MARK: - Cancellation
 
     public override func cancel() {
         if !finished {

        get {
            var _dependencies = super.dependencies
            guard let
                waiter = waitForDependenciesOperation,
                index = _dependencies.indexOf(waiter) else {
                    return _dependencies
            }



public extension Operation {

    private func createDidFinishDependenciesOperation() -> NSOperation {
        assert(waitForDependenciesOperation == nil, "Should only ever create the finishing dependency once.")
        let __op = NSBlockOperation { }
