javascript - Use superscript in d3 -

how use superscript in d3? have following code:

var counter = 2; textnode.text("event" + counter);// want counter superscript 

should use:

textnode.style(args); 

to add superscripts?

use select tag , use text set text

d3.select('sup').text("event" + counter) 

or if need create

d3.select('body').append('sup').text("event" + counter)