Bug 305703 [Viewers][CommonNavigator] remembered contributions can leak when using filters
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* @see org.eclipse.jface.viewers.Viewer#setInput(java.lang.Object)
	 */
	public final void setInput(Object input) {
		try {
			
			unmapAllElements();
			super.setInput(input);
		} finally {
			
		}
	}
	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.jface.viewers.Viewer#setSelection(org.eclipse.jface.viewers.ISelection, boolean)
	 */
	public void setSelection(ISelection selection, boolean reveal) {
		/**
		 * <p>
		 * If the new selection differs from the current selection the hook
		 * <code>updateSelection</code> is called.
		 * </p>
		 * <p>
		 * If <code>setSelection</code> is called from within
		 * <code>preserveSelection</code>, the call to
		 * <code>updateSelection</code> is delayed until the end of
		 * <code>preserveSelection</code>.
		 * </p>
		 * <p>
		 * Subclasses do not typically override this method, but implement
		 * <code>setSelectionToWidget</code> instead.