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/views/markers/internal/MarkerGroup.java
}
	/**
	 * Get the attribute mapping for the marker
	 * 
	 * @param marker
	 * @return MarkerGroupingEntry
	 */
	private MarkerGroupingEntry getMapping(ConcreteMarker marker) {
		if (marker.getGroup() == null) {
			marker.setGroup(findGroupValue(marker));
		}
		return (MarkerGroupingEntry) marker.getGroup();
	}
	/**
	 * Return the markerField for the receiver.
	 * 
	 * @return MarkerField
	 */
	public MarkerField getMarkerField() {
		return markerField;
	}
	/**
	 * Return the marker types that match and are subtypes of markerType.
	 * 
	 * @param markerType
	 * @return MarkerType[]
	 */
	private MarkerType[] getMarkerTypes(String markerType) {
		MarkerTypesModel model = MarkerTypesModel.getInstance();
		Collection types = new HashSet();