Tooltip widget makes graph disappear if used in node builder callback

[r-durao-pvotal]

Steps to reproduce:

1. Go to one of the example's code from the example app
2. Wrap the node widget with a Tooltip
3. Run the app
4. Go to that graph
5. Hover your mouse on one of the nodes
6. Observe app behavior

Expected Behavior: Graph should behave normally and the tooltip should be rendered
Actual Behavior: Graph disappears.