The preview of Vaadin addons doens’t show the image. It’s visible for less than a half seconds before it disappears.
Tested it on Firefox and Chrome on different computers.
https://vaadin.com/directory/component/twincolselect
![screenshot]
(http://cloud.screenpresso.com/Qg0Hd/2020-01-16_17h02_24.png)
JavaScript Error
twincolselect:1 Uncaught ReferenceError: $ is not defined
at HTMLImageElement.onload (twincolselect:1)