     }
     
     func testColorArtworkAnalyzing() {
-        testImages.forEach() { image in
-            let ca = CAColorArtwork(image: image)
+        measure {
+            let ca = CAColorArtwork(image: self.testImage)
             ca.analyze()
             XCTAssertNotNil(ca.backgroundColor)
         }

        let fileURL = bundle.urlForImageResource("Stadium Arcadium")!
        let img = NSImage(contentsOf: fileURL)!
        let cgimg = img.cgImage(forProposedRect: nil, context: nil, hints: nil)!
        testImages = [cgimg]
    }
    
    override func tearDown() {


class Tests: XCTestCase {
    
    var testImage: CGImage!
    
    override func setUp() {
        super.setUp()
