This test replaces all the items and
sets each new option's selected attr to false,
then set the zero'th item to true (selected)


This test replaces all the items and
sets each new option's selected attr to true
(so for the first two selects only the first item should be selected,
for the last select all the items should be selected)

Combobox	Single Select	Multiple Select
Select Black White	Select Black White	Select Black White

Another test (1) can be found here
Another test (3) can be found here