Bug 163317 [Viewers] Take over SWT programming pattern to JFace Viewers
To open ColumnViewer for reusablility we should not make it final making the constructor protected forces people to subclass it and not directly creating instances from it.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/CellLabelProvider.java
*            the element for which the tool tip is shown
	 * @return {@link Image} or <code>null</code> if there is not image.
	 */
	public Image getToolTipImage(Object object) {
		return null;
	}
	/**
	 * Returns the tool tip text for the given element and column index, or
	 * <code>null</code> if a custom tool tip should not be displayed.
	 * 
	 * @param element
	 *            the element for which the tool tip is shown
	 * @return the {@link String} to be displayed in the tool tip, or
	 *         <code>null</code> if a custom tool tip should not be displayed
	 */
	public String getToolTipText(Object element) {
		return null;
	}
	/**
	 * Return the background color used for the tool tip
	 * 
	 * @param object
	 *            the {@link Object} for which the tool tip is shown
	 * 
	 * @return the {@link Color} used or <code>null</code> if you want to use
	 *         the
	 */
	public Color getToolTipBackgroundColor(Object object) {
		return null;
	}