Bug 221337 [Markers] MarkerItem has too much API
We are exposing too much as API in MarkerItem. We should only provide getAtttributeValue and the methods that support PATH_ATTRIBUTE and NAME_ATTRIBUTE as they are tricky. Everything else needs to be pushed down to an internal class. We should mention the relevant IMarker constants for those removed.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
loadFiltersPreference();
		}
		return filters;
	}
	/**
	 * Return the categories for the receiver.
	 * 
	 * @return MarkerItem[] or <code>null</code> if there are no
	 *         categories.
	 */
	public MarkerItem[] getCategories() {
		if (building) {
			return null;
		}
		return categories;
	}
	/**
	 * Return the group used to generate categories.
	 * 
	 * @return MarkerGroup or <code>null</code>.
	 */
	MarkerGroup getCategoryGroup() {
		return categoryGroup;
	}
	/**
	 * Return a new instance of the receiver with the field
	 * 
	 * @return MarkerComparator
	 */