initRenderView method Null safety
Creates a RenderView object to be the root of the RenderObject rendering tree, and initializes it so that it will be rendered when the next frame is requested.
Called automatically when the binding is created.
Implementation
void initRenderView() {
assert(!_debugIsRenderViewInitialized);
assert(() {
_debugIsRenderViewInitialized = true;
return true;
}());
renderView = RenderView(configuration: createViewConfiguration(), window: window);
renderView.prepareInitialFrame();
}