Bug 214649 [Markers] Allow markerAttributeGroupings and markerGroups to be specified within contentGenerators
With everything at the top level it is hard to see the relation to a contentGenerator and the groups and attribute groupings. These should be sub elements a la menus.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerSupportRegistry.java
*/
	public TableComparator getSorterFor(String type) {
		if (hierarchyOrders.containsKey(type)) {
			return (TableComparator) hierarchyOrders.get(type);
		}
		TableComparator sorter = findSorterInChildren(type, getRootType());
		if (sorter == null) {
			return new TableComparator(new IField[0], new int[0], new int[0]);
		}
		return sorter;
	}
	/**
	 * Return the list of root marker types.
	 * 
	 * @return List of MarkerType.
	 */
	private MarkerType getRootType() {
		if (rootType == null) {
			rootType = (MarkerTypesModel.getInstance())
					.getType(IMarker.PROBLEM);
		}
		return rootType;
	}
	/**
	 * Find the best match sorter for typeName in the children. If it cannot be
	 * found then return <code>null</code>.
	 * 
	 * @param typeName
	 * @param type
	 * @return TableSorter or <code>null</code>.