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
String defaultEntryId = attributeGrouping.getDefaultGroupingEntry();
			if (defaultEntryId != null) {
				if (entryIDsToEntries.containsKey(defaultEntryId)) {
					MarkerGroupingEntry entry = (MarkerGroupingEntry) entryIDsToEntries
							.get(defaultEntryId);
					entry.setAsDefault(attributeGrouping.getMarkerType());
				} else {
					IDEWorkbenchPlugin.log(NLS.bind(
							"Reference to invalid markerGroupingEntry {0}",
							defaultEntryId));
				}
			}
			IConfigurationElement[] mappings = attributeGrouping.getElement()
					.getChildren(ATTRIBUTE_MAPPING);
			for (int i = 0; i < mappings.length; i++) {
				String entryId = mappings[i]
						.getAttribute(MARKER_GROUPING_ENTRY);
				if (entryIDsToEntries.containsKey(entryId)) {
					MarkerGroupingEntry entry = (MarkerGroupingEntry) entryIDsToEntries
							.get(entryId);
					entry.getMarkerGroup().mapAttribute(attributeGrouping,
							entry, mappings[i].getAttribute(VALUE));
				} else {
					IDEWorkbenchPlugin.log(NLS.bind(
							"Reference to invaild markerGroupingEntry {0}", 
							defaultEntryId));
				}
			}
		}
	}