Styling the text in the elements of a flowchart

[stephen-ciq]

I have searched the documentation for a way to style the text in the blocks of a flowchart but could not find anything. Specifically I am trying to underline links so that they look more like links.

So for example I want to add to this example:

graph LR;
    A-->B;
    click A callback "Tooltip for a callback"
    click B "http://www.github.com" "This is a tooltip for a link"
    style B  text-decoration: underline

but that does not seem to work.