Bug 255229 [Viewers] [3.5] NPE in ColumnViewerToolTipSupport
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewerToolTipSupport.java
*/
	protected Composite createToolTipContentArea(Event event, Composite parent) {
		ViewerCell cell = (ViewerCell) getData(VIEWER_CELL_KEY);
		setData(VIEWER_CELL_KEY, null);
		return createViewerToolTipContentArea(event, cell, parent);
	}
	/**
	 * Creates the content area of the tool tip giving access to the cell the
	 * tip is shown for. Subclasses can overload this method to implement their
	 * own tool tip design.
	 *
	 * <p>
	 * This method is called from
	 * {@link #createToolTipContentArea(Event, Composite)} and by default calls
	 * the {@link DefaultToolTip#createToolTipContentArea(Event, Composite)}.
	 * </p>
	 *
	 * @param event
	 *            the event that which
	 * @param cell
	 *            the cell the tool tip is shown for
	 * @param parent
	 *            the parent of the control to create
	 * @return the control to be displayed in the tool tip area
	 * @since 3.4
	 */
	protected Composite createViewerToolTipContentArea(Event event,
			ViewerCell cell, Composite parent) {
		return super.createToolTipContentArea(event, parent);
	}