How to make scrollable vertical NSStackView

import AppKit
import Anchors
import Omnia

final class ScrollableStackView: NSView {
    final class FlippedClipView: NSClipView {
        override var isFlipped: Bool {
            return true
        }
    }

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        setup()
    }

    required init?(coder decoder: NSCoder) {
        fatalError()
    }

    let stackView: NSStackView = withObject(NSStackView()) {
        $0.orientation = .vertical
    }

    private let scrollView: NSScrollView = NSScrollView()

    private func setup() {
        addSubview(scrollView)
        scrollView.hasVerticalScroller = true
        scrollView.drawsBackground = false

        activate(
            scrollView.anchor.edges
        )

        let clipView = FlippedClipView()
        clipView.translatesAutoresizingMaskIntoConstraints = false

        clipView.drawsBackground = false
        scrollView.contentView = clipView

        activate(
            clipView.anchor.edges.equal.to(scrollView.anchor)
        )

        scrollView.documentView = stackView
        stackView.translatesAutoresizingMaskIntoConstraints = false
        activate(
            clipView.anchor.left.top.right.equal.to(stackView.anchor)
        )
    }
}