How many outputs does a chart node have?

I thought the chart node had just one output, and that is what I see when I add a ui-chart node. However, when I import the example flow from the bottom of https://github.com/node-red/node-red-dashboard/blob/master/Charts.md all the chart nodes appear to have two outputs.
Dashboard 2.22.1 on 1.1 beta and 1.0.3

I saw a comment in the node file where it looks like, at one time there were two outputs on the chart node.

correct - cor - I really must update that example... the second output was just to detect a connection to trigger a reload - now in the ui_control node.