title: How to keep selections highlighted in a tkinter Listbox?
body: <p>I have 2 separated List-boxes set on single selection mode. When I select an item from <code>listboxA</code>, it gets highlighted, but when I select an item from <code>listboxB</code>, it gets highlighted, and the item from <code>listboxA</code> remains active, but isn't highlighted. How can I keep both highlighted?</p>