How do I unset a token if a click value is has the same value?

Hello All, I have a pie chart divided into slices. When I click a slice it sets a token `tok_slice_value` with `click.value` which causes some other fun stuff to happen on the dashboard. If I click on another slice then the token gets updated with that new `click.value`. What I would like to do is unset the token if the token value is the same as the new `click.value`. I think I've got it, but I just cannot get the right syntax. Here's what I have:$click.value$ Doesn't work unfortunately and I've tried a number of different options to no avail. Can someone please help me? Thanks! Andrew