How Do I Use Mutationobserver Instead Of Mutation Events?

I am trying to create my first streamgraph with D3.js. I am starting with a working example which incorporates a tooltip from code posted on-line, http://bl.ocks.org/WillTurman/46

Solution 1:

This is something that will need to be changed in the D3 source. As a user (and certainly as a beginner), you don't need to worry about this -- the warning is only relevant to the developers. Feel free to open an issue about this.