contentsize and contentOffset equivalent in NSScroll view

I am porting an app from Ipad to mac. (I know that it sounds weird)

I stuck with NSScrollview. Please guide me contentsize , contentOffset equivalent in NSScrollview.

UIScrollView* uiScroll;
uiScroll.contentSize;
uiScroll.contentOffset;
uiScroll.contentSize = CGSizeMake(w,h);
uiScroll.contentOffset = CGPointMake(x,y);

=

NSScrollView* nsScroll;
nsScroll.documentView.frame.size;
nsScroll.documentVisibleRect.origin;
nsScroll.documentView.frameSize = NSMakeSize(w,h);
[nsScroll.documentView scrollPoint:NSMakePoint(x,y)];

Or perhaps even better:

import AppKit

extension NSScrollView {
    var documentSize: NSSize {
        set { documentView?.setFrameSize(newValue) }
        get { documentView?.frame.size ?? NSSize.zero }
    }
    var documentOffset: NSPoint {
        set { documentView?.scroll(newValue) }
        get { documentVisibleRect.origin }
    }
}

Notes: I used 'documentSize' (and 'documentOffset') because 'contentSize' conflicts with an already existing property of NSScrollView.