dispose method
void
dispose()
Dispose owned frame pipeline state.
Implementation
void dispose() {
final root = _rootRenderObject;
if (root != null) {
clearRootRenderObject(root);
}
if (_ownsPipelineOwner) {
pipelineOwner.dispose();
}
_pointerRouter.dispose();
focusManager.dispose();
_dirty.clear();
_dirtySet.clear();
}