     
     func numberToStringThrows(number: Int) -> Future<String> {
         let promise = Promise<String>()
-        let dispatchTime = dispatch_time(DISPATCH_TIME_NOW, Int64(0.1 * Double(NSEC_PER_SEC)))
-        dispatch_after(dispatchTime, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0)) {
+        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
             promise.reject(TestError.FailedToConvertNumberToString(number))
         }
         return promise.future

            failureExpectation.fulfill()
        }
        
        self.waitForExpectationsWithTimeout(10, handler: nil)
    }
    
    

            }
        }
        
        self.waitForExpectationsWithTimeout(1, handler: nil)
    }
    
    func testFailurePromiseFunctionComposition() {
