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
* </p>
 * <p>
 * If the caller adds its own columns, uses <code>Table.setHeadersVisible(true)</code>, 
 * or needs to handle dynamic resizing of the table, it is recommended to  
 * create the <code>Table</code> itself, specifying the <code>SWT.CHECK</code> style bit 
 * (along with any other style bits needed), and use <code>new CheckboxTableViewer(Table)</code> 
 * rather than this constructor.
 * </p>
 * 
 * @param parent the parent control
 * @param style SWT style bits
 * 
 * @deprecated use newCheckList(Composite, int) or new CheckboxTableViewer(Table) 
 *   instead (see above for details)
 */
public CheckboxTableViewer(Composite parent, int style) {
	this(createTable(parent, style));
}
/**
 * Creates a table viewer on a newly-created table control under the given parent.
 * The table control is created using the given SWT style bits, plus the 
 * <code>SWT.CHECK</code> style bit.
 * The table shows its contents in a single column, with no header.
 * The viewer has no input, no content provider, a default label provider, 
 * no sorter, and no filters.
 * <p>
 * No <code>TableColumn</code> is added. SWT does not require a 
 * <code>TableColumn</code> if showing only a single column with no header.
 * SWT correctly handles the initial sizing and subsequent resizes in this case.
 *