What is the correct block syntax in Swift

so I am rewriting some Obj-C code in Swift and stumbled across a block which drives me crazy.
I’ve already had a look at the documentation provided by apple and some other resources here on stackoverflow. Unfortunately, I couldn’t find the solution, yet. IÄve got that piece of obj-c code which I want to re-write in Swift. Maybe you can help me figuring out how to do that. I’d really appreciate it!

- (void)startSearchWithCompletionHandler:(PHBridgeSearchCompletionHandler)completionHandler;

And gets called like this:

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  • [self.bridgeSearch startSearchWithCompletionHandler:^(NSDictionary *bridgesFound) { ...
    

    So far I came up with this:

    var bridgeSearching : PHBridgeSearching = ...
    
    bridgeSearching.startSearchWithCompletionHandler { (bridgesFound: AnyObject!) -> PHBridgeSearchCompletionHandler in
    }
    

    Solutions Collect From Internet About “What is the correct block syntax in Swift”

    If the block signature is

    void (^PHBridgeSearchCompletionHandler) (NSDictionary *)
    

    then the closure should look like:

    { (bridgesFound: NSDictionary?) -> () in
        ...
    }
    

    but if you know the dictionary contains object of the same type, let’s say Int, and the key type is String, then you can also write it as

    { (bridgesFound: [String:Int]) -> () in
        ...
    }
    

    Up to you whether to make it optional or not, depending on how you are using it.