function forEachSingleChildDummy(traverseContext, child, name) {
  return null;
}
Replaces all of the state. Always use this or `setState` to mutate state.
You should treat `this.state` as immutable.

There is no guarantee that `this.state` will be immediately updated, so
accessing `this.state` after calling this method may return the old value.

@param {ReactClass} publicInstance The instance that should rerender.
@param {object} completeState Next state.
@internal