You'd think that calling something like this will always remove the *green-rect* style:

rect.getStyleClass().remove("green-rect");

but it actually wont if some framework/library/other class/etc. added the *green-rect" style twice.

This is VERY counter-intuitive and error prome.

Full example:

https://bitbucket.org/walczak_it/prodoko-base/src/92b0de66d4c6b03812e651d04173a241b2639586/prodoko-sandbox/src/main/java/StyleClassesTestApp.java?at=master

https://bitbucket.org/walczak_it/prodoko-base/src/92b0de66d4c6b03812e651d04173a241b2639586/prodoko-sandbox/src/main/resources/styleClassesTest.css?at=master
return 0;
it will show a green rectangle.