 
     /// Conforms to `OperationDidCancelObserver`, executes the block
     public func didCancelOperation(operation: Operation) {
-        block(operation)
+        block(operation: operation)
+    }
+
+    /// Base OperationObserverType method
+    public func didAttachToOperation(operation: Operation) {
+        didAttachToOperation?(operation: operation)
     }
 }
 

 closure when the operation is about to finish.
 */
public struct WillFinishObserver: OperationWillFinishObserver {
    public typealias BlockType = (Operation, [ErrorType]) -> Void

    private let block: BlockType

    /**
     Initialize the observer with a block.


    /// Conforms to `OperationDidStartObserver`, executes the block
    public func didStartOperation(operation: Operation) {
        block(operation: operation)
    }

    /// Base OperationObserverType method
    public func didAttachToOperation(operation: Operation) {
        didAttachToOperation?(operation: operation)
    }
}

