Bug 257855 [CommonNavigator] Supporting Custom Transfertypes in Common Navigator Framework
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonViewer.java
}
		super.unmapElement(element, item);
	}
	/*
	 * @see StructuredViewer#unmapAllElements()
	 */
	protected void unmapAllElements() {
		if (_mapper != null)
			_mapper.clearMap();
		super.unmapAllElements();
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.viewers.AbstractTreeViewer#setSelectionToWidget(java.util.List, boolean)
	 */
	protected void setSelectionToWidget(List v, boolean reveal) {
		clearSelectionCache();
		super.setSelectionToWidget(v, reveal);
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.jface.viewers.AbstractTreeViewer#handleDoubleSelect(org.eclipse.swt.events.SelectionEvent)
	 */
	protected void handleDoubleSelect(SelectionEvent event) {
		clearSelectionCache();
		super.handleDoubleSelect(event);
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.jface.viewers.StructuredViewer#handleOpen(org.eclipse.swt.events.SelectionEvent)
	 */