Bug 106574 [KeyBindings] registry: General/Keys setting not saved or not restored
bundles/org.eclipse.jface/src/org/eclipse/jface/bindings/BindingManager.java
* is an exact match). The available completions is a map of trigger (<code>TriggerSequence</code>)
	 * to bindings (<code>Binding</code>). This value may be
	 * <code>null</code> if there is no existing solution.
	 */
	private Map prefixTable = null;
	/**
	 * The map of scheme identifiers (<code>String</code>) to scheme (
	 * <code>Scheme</code>). This value may be empty, but is never
	 * <code>null</code>.
	 */
	private final Map schemesById = new HashMap();
	/**
	 * <p>
	 * Constructs a new instance of <code>BindingManager</code>.
	 * </p>
	 * <p>
	 * This method completes in amortized constant time (O(1)).
	 * </p>
	 * 
	 * @param contextManager
	 *            The context manager that will support this binding manager.
	 *            This value must not be <code>null</code>.
	 * @param commandManager
	 *            The command manager that will support this binding manager.
	 *            This value must not be <code>null</code>.
	 */
	public BindingManager(final ContextManager contextManager,
			final CommandManager commandManager) {
		if (contextManager == null) {
			throw new NullPointerException(