Bug 32254 [Viewers] AbstractTreeViewer uses HashSet to remember expansion state
I20030216 The custom hash table should be used instead. Otherwise expansion state may be lost due to a different equals implementation of the element and the IElementComparer.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CheckboxTableViewer.java
* @param parent the parent control
 * @param style SWT style bits
 * 
 * @since 2.0
 */
public static CheckboxTableViewer newCheckList(Composite parent, int style) {
	Table table = new Table(parent, SWT.CHECK | style);
	return new CheckboxTableViewer(table);
}
/**
 * Creates a table viewer on the given table control.
 * The <code>SWT.CHECK</code> style bit must be set on the given table control.
 * The viewer has no input, no content provider, a default label provider, 
 * no sorter, and no filters.
 *
 * @param table the table control
 */
public CheckboxTableViewer(Table table) {
	super(table);
}
/* (non-Javadoc)
 * Method declared on ICheckable.
 */
public void addCheckStateListener(ICheckStateListener listener) {
	checkStateListeners.add(listener);
}
/**
 * Creates a new table control with one column.
 *
 * @param parent the parent control