Bug 258810 [Markers] Markers for the entire workspace show up when working set empty
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerFieldFilterGroup.java
* @return boolean
	 */
	public boolean isEnabled() {
		return enabled;
	}
	/**
	 * Return whether or not this is a system or user group.
	 * 
	 * @return boolean <code>true</code> if it is a system group.
	 */
	public boolean isSystem() {
		return element != null;
	}
	/**
	 * Load the settings from the legacy child.
	 * 
	 * @param memento
	 */
	void legacyLoadSettings(IMemento memento) {
		String enabledString = memento.getString(TAG_ENABLED);
		if (enabledString != null && enabledString.length() > 0)
			enabled = Boolean.valueOf(enabledString).booleanValue();
		Integer resourceSetting = memento
				.getInteger(MarkerFilter.TAG_ON_RESOURCE);
		if (resourceSetting != null)
			scope = resourceSetting.intValue();
		String workingSetName = memento.getString(TAG_WORKING_SET);
		if (workingSetName != null)
			setWorkingSet(PlatformUI.getWorkbench().getWorkingSetManager()
					.getWorkingSet(workingSetName));