How can I have only icons of applications in the tasklist in awesome 3.5?

How can I have only icons of applications in the tasklist in awesome 3.5?

In awesome 3.4 there was a way to do this:
mytasklist[s] = awful.widget.tasklist(function(c)
local task = { awful.widget.tasklist.label.currenttags(c, s) }
return '', task[2], task[3], task[4]
end, mytasklist.buttons)
But in awesome 3.5 that doesn't work anymore, any solutions?
Thank you