             }
         }
         
-        let sut = MemoryCacheMock()
+        let sut = MemoryCacheMock("test")
         sut.expectation = expectation // XCode crashes if we use the original expectation directly
         
         NSNotificationCenter.defaultCenter().postNotificationName(UIApplicationDidReceiveMemoryWarningNotification, object: nil)

    }
    
    func testFetchImage () {
        let sut = MemoryCache()
        let key = "key"
        
        XCTAssert(sut.fetchImage(key) == nil, "MemoryCache is empty")

    }
    
    func testRemoveImageExisting() {
        let sut = MemoryCache("test")
        let key = "key"
        sut.setImage(UIImage(), key)
        
