message: Retained current scene data
diff: @@ -5,7 +5,7 @@ import { View } from 'react-native';
  import spring from './spring.js'
  class NavigationMotion extends React.Component<any, any> {
  - private onNavigate = (oldState, state, data, asyncData) => {
  + private onNavigate = (oldState, state, data) => {
  this.setState((prevState) => {
  var {url, crumbs} = this.getStateNavigator().stateContext;
  var scenes = {};
  @@ -13,7 +13,7 @@ class NavigationMotion extends React.Component<any, any> {
  for(var i = 0; i < crumbs.length; i++)
  scenes[crumbs[i].url] = previousScene = prevState.scenes[crumbs[i].url];
  var previousSceneData = previousScene && previousScene.data;
  - scenes[url] = {element: state.renderScene(data, this.moveScene(url), previousSceneData)};
  + scenes[url] = {...prevState.scenes[url], element: state.renderScene(data, this.moveScene(url), previousSceneData)};
  return {scenes};
  });
  }
  