A reference to the parent of this window.
If this WindowBase has no parent, parent will return a reference to the WindowBase itself.
IFrameElement myIFrame = new IFrameElement();
window.document.body.elements.add(myIFrame);
print(myIframe.contentWindow.parent == window) // 'true'
print(window.parent == window) // 'true'
Source
WindowBase get parent;