     }
 
     func testMergeAdjacentWhitespaces() {
-        var subtitleConverter = try! SubtitleConverter(subtitles: "01:12:33:Text  with   ugly spaces.")
+        let subtitleConverter = try! SubtitleConverter(subtitles: "01:12:33:Text  with   ugly spaces.")
         subtitleConverter.mergeAdjacentWhitespaces = true
 
         let convertedSubtitles = try! subtitleConverter.convert(to: .tmplayer)


    func testOffset() {
        // Positive offset.
        var subtitleConverter = try! SubtitleConverter(subtitles: "01:01:01:Text.")
        subtitleConverter.frameRate = 1.0
        subtitleConverter.offset = 1000 // 1 second
        XCTAssertEqual(try! subtitleConverter.convert(to: .mpl2), "[36620][36670]Text.")


    func testFrameRate() {
        // Time Based format to Frame Based format.
        let timeBasedSubtitleConverter = try! SubtitleConverter(subtitles: "[3600][7200]Text.")

        timeBasedSubtitleConverter.frameRate = 2.0
        XCTAssertEqual(try! timeBasedSubtitleConverter.convert(to: .mpl2), "[3600][7200]Text.")
