Bug 215004 [Markers] New Problems view: 'Group by > Type' broken
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerGroup.java
MarkerGroupingEntry entry = mapping.testAttribute(marker);
					if (entry != null) {
						return entry;
					}
				} else {
					
					defaultMapping = mapping;
				}
			}
			if (defaultMapping != null) {
				return defaultMapping.groupingEntry;
			}
		}
		return undefinedEntry;
	}
	/**
	 * Return the field for the receiver.
	 * 
	 * @return {@link IField}
	 */
	public IField getField() {
		return field;
	}
	/**
	 * Return the id of the receiver.
	 * 
	 * @return String
	 */
	public String getId() {
		return id;