         var chain: TimePeriodChain = TimePeriodChain()
         //Create test TimePeriods to construct same as control
         //Add test periods
-        collectionSame.addTimePeriod(firstPeriod)
-        collectionSame.addTimePeriod(secondPeriod)
-        collectionSame.addTimePeriod(thirdPeriod)
-        collectionSame.addTimePeriod(fourthPeriod)
-        chain.addTimePeriod(firstPeriod)
-        chain.addTimePeriod(secondPeriod)
-        chain.addTimePeriod(thirdPeriod)
-        chain.addTimePeriod(fourthPeriod)
+        collectionSame.add(firstPeriod)
+        collectionSame.add(secondPeriod)
+        collectionSame.add(thirdPeriod)
+        collectionSame.add(fourthPeriod)
+        chain.add(firstPeriod)
+        chain.add(secondPeriod)
+        chain.add(thirdPeriod)
+        chain.add(fourthPeriod)
         //Test same as control
         XCTAssertTrue(self.controlCollection.hasSameCharacteristicsAs(collectionSame))
         //Test differnt chain

    
    var formatter = DateFormatter()
    var controlCollection = TimePeriodCollection()
    
    override func setUp() {
        //Initialize control TimePeriodChain
        self.controlCollection = TimePeriodCollection()
        //Initialize formatter
        self.formatter = DateFormatter()
        self.formatter.dateFormat = "yyyy MM dd HH:mm:ss.SSS"
        //Create test TimePeriods that are 1 year long
        var firstPeriod = TimePeriod(startDate: self.formatter.dateFromString("2014 11 05 18:15:12.000"), endDate: self.formatter.dateFromString("2015 11 05 18:15:12.000"))
        var secondPeriod = TimePeriod(startDate: self.formatter.dateFromString("2015 11 05 18:15:12.000"), endDate: self.formatter.dateFromString("2016 11 05 18:15:12.000"))
        var thirdPeriod = TimePeriod(startDate: self.formatter.dateFromString("2016 11 05 18:15:12.000"), endDate: self.formatter.dateFromString("2017 11 05 18:15:12.000"))
        var fourthPeriod = TimePeriod(startDate: self.formatter.dateFromString("2015 4 05 18:15:12.000"), endDate: self.formatter.dateFromString("2017 4 05 18:15:12.000"))
        //Add test periods
        self.controlCollection.addTimePeriod(firstPeriod)
        self.controlCollection.addTimePeriod(secondPeriod)
        self.controlCollection.addTimePeriod(thirdPeriod)
        self.controlCollection.addTimePeriod(fourthPeriod)
    }
    
    override func tearDown() {

    }
    
    // MARK: - Group Info
    func testDurationInWeeks() {
        XCTAssertEqual(156, self.controlCollection.durationInWeeks)
    }
