mount method
Adds this element to the tree at the given parent.
Implementation
@override
void mount(Element? parent) {
super.mount(parent);
final renderObject = this.renderObject
as ContainerRenderObjectMixin<RenderObject, ParentData>;
_children = (widget as MultiChildRenderObjectWidget).children.map((w) {
final child = w.createElement();
child.mount(this);
if (child.renderObject != null) {
renderObject.setupParentData(child.renderObject!);
renderObject.add(child.renderObject!);
}
return child;
}).toList();
}