        let scaledSize = CGSize(width: 10, height: 5).sizeWithScale(2)
        XCTAssertTrue(CGSize(width: 20, height: 10) == scaledSize)
    }
    
    func testScalingWithNegativeScale() {
        let scaledSize = CGSize(width: 10, height: 5).sizeWithScale(-3)
        XCTAssertTrue(CGSize(width: -30, height: -15) == scaledSize)
    }
    
    func testCenterPointInLargerSize() {
        let size = CGSize(width: 10, height: 20)
        let largerSize = CGSize(width: 50, height: 100)
        
        XCTAssertTrue(CGPoint(x: 20, y: 40) == size.centerPointInSize(largerSize))