1) Open CSS dilaog on some CSS file
2) Print some name of a new CSS styleclass
3) Go to preview
ASSERT: Preview shows new created styleclass at the end of the list. Everything is correctly.
4) Print another name of CSS styleclass
ASSERT: Preview shows correct state of new CSS style class
5) Check combobox
RESULT: The name of the class from step 2 exists too, but the preview doesn't show it.
We can repeat these steps and all styleclasses will be shown in comboBox. I think, that combobox and preview should show only current classes in css file and styleclasses that was created and saved using CSS dialog.