I'm working on a new extension for a custom visualization, and I can't find anything on this in the documentation. Is there a way to conditionally show items on the accordion panel during editing? For example, in a standard visualization, if you go into Appearance>Colors and Legend>Colors, and toggle it to "Custom", new items appear underneath. Then if you pick another item in the dropdown, more options appear.. I want to do the same thing, basically. I would ideally have a dropdown that conditionally exposes either a text box for expression entry, or a color picker. I already know about accessing the values of each item, so once I get it set up I already have the rest of the code in place.