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

class MemoryCacheTests: XCTestCase {
    
    func testInit() {
        let sut = MemoryCache()
        XCTAssertNotNil(sut.memoryWarningObserver)
    }
    
    func testDeinit() {
        weak var sut = MemoryCache()
    }
    
    func testSetImage () {
        let sut = MemoryCache()
        let image = UIImage()
        let key = "key"
        

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