Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/INavigatorContentDescriptor.java
*         
	 * @since 3.5        
	 */
	public int getSequenceNumber();
	
	/**
	 * The enabledByDefault attribute specifies whether an extension should be
	 * activated in the context of a viewer automatically. Users may override
	 * this setting through the "Types of Content" dialog. This will be true
	 * if either the activeByDefault attribute of the navigatorContent element 
	 * is true, or if an initialActivationExpression is specified which resolves
	 * to true.
	 * 
	 * @return true if the extension is enabled by default.
	 */
	boolean isActiveByDefault();
	/**
	 * True if this content extension is used only to specify a commonSorter 
	 * in order to provide only sorting.
	 * @return true if sort only
	 * 
	 * @since 3.5
	 */
	boolean isSortOnly();
	
	/**
	 * Determine if this content extension is enabled for the given element.
	 * 
	 * @param anElement
	 *            The element that should be used for the evaluation.