The CCombo class represents a selectable user interface object
that combines a text field and a list and issues notification
when an item is selected from the list.
Note that although this class is a subclass of Composite,
it does not make sense to add children to it, or set a layout on it.
Note that although this class is a subclass of
Composite, it does not make sense to add children to it, or set a layout on it.