What with start point coordinate on mac os?

Question

What's going on? I want customize macOS button with swift 3. macOS (0.0, 0.0) point is in bottom left corner. But when I write this code:

    let path = NSBezierPath()
    path.lineWidth = 2

    path.move(to: NSPoint(x: 0.0, y: 0.0))
    path.line(to: NSPoint(x: 0.0, y: 1.0))
    path.close() 

    NSColor.red.setStroke()
    path.stroke()

My start (0.0, 0.0) point is in top left corner, why?