Autocomplete: Implement _elementsFromFromClassKey()
Accordion: Implementing _elementsFromClassKey()
Button: Implementing _elementsFromClassKey()

Also for buttonset.
Dialog: Implement _elementsFromClassKey()
Menu: Implement _elementsFromClassKey()
Progressbar: Implement _elementsFromClassKey()
Selectmenu: Implement _elementsFromClassKey()
Slider: Implement _elementsFromClassKey()
Spinner: Implement _elementsFromClassKey()
Tabs: Implement _elementsFromClassKey()
Tooltip: Implement _elementsFromClassKey()