TreeView组件 按照官方demo 显示异常

首次渲染页面没问题，点击根目录后就会报错。就是说 不显示子节点。

`Invariant Violation: Text strings must be rendered within a component.

This error is located at:
in RCTView (at View.js:35)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at TouchableOpacity.js:308)
in TouchableOpacity (created by TreeView)
in RCTView (at View.js:35)
in View (created by TreeView)
in RCTView (at View.js:35)
in View (created by TreeView)
in RCTView (at View.js:35)
in View (created by TreeView)
in RCTView (at View.js:35)
in View (created by TreeView)
in RCTView (at View.js:35)
in View (created by TreeView)
in TreeView (at treeView.js:42)
in TreeViewScreen
in RCTView (at View.js:35)
in View
in Unknown (at renderApplication.js:40)
in RCTView (at View.js:35)
in View (at AppContainer.js:98)
in RCTView (at View.js:35)
in View (at AppContainer.js:115)
in AppContainer (at renderApplication.js:39)`

Start by reproducing the issue from the official TreeView demo: render the tree and tap the root directory. Inspect the TreeView component around treeView.js:42 and follow the failing child-node render associated with the reported Text invariant. Done means expanding the root displays its child nodes without the error.