Bug 190061 [Metadata] Update @since tags for new API
Patch to follow
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
return null;
	}
		
	/**
	 * This implementation of {@link #getItemAt(Point)} returns null to ensure
	 * API backwards compatibility. Subclasses should override.
	 * 
	 * @since 3.3
	 */
	protected Item getItemAt(Point point) {
		return null;
	}
	
	/**
	 * This implementation of {@link #createViewerEditor()} returns null to ensure
	 * API backwards compatibility. Subclasses should override.
	 *
	 * @since 3.3
	 */
	protected ColumnViewerEditor createViewerEditor() {
		return null;
	}
	
	/**
	 * Returns the number of columns of this viewer.
	 * <p><b>Subclasses should overwrite this method, which has a default
	 * implementation (returning 0) for API backwards compatility reasons</b></p>
	 *
	 * @return the number of columns
	 *