Bug 323489 [KeyBindings] Reduce memory footprint of BindingManager
bundles/org.eclipse.jface/src/org/eclipse/jface/bindings/BindingManager.java
*/
	private String platform = Util.getWS();
	/**
	 * The array of platforms, starting with the active platform and moving up
	 * through less specific representations of the platform. For example,
	 * ["gtk", "", null]. This value will never be <code>null,/code>.
	 */
	private String[] platforms = expand(platform, Util.ZERO_LENGTH_STRING);
	/**
	 * A map of prefixes (<code>TriggerSequence</code>) to a map of
	 * available completions (possibly <code>null</code>, which means there
	 * 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;
	/**
	 * <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>.