Bug 167170 [Markers] Need to check for duplicate filter names
M3 It is currently possible to enter duplicate filter names
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/DialogMarkerFilter.java
*/
		public abstract boolean isCategory();
	}
	/**
	 * MarkerTypeNode is the wrapper for marker types.
	 * 
	 */
	private class MarkerTypeNode extends AbstractNode {
		MarkerType type;
		MarkerCategory category;
		/**
		 * Create an instance of the receiver wrapping markerType.
		 * 
		 * @param markerType
		 */
		public MarkerTypeNode(MarkerType markerType) {
			type = markerType;
			nodeToTypeMapping.put(markerType.getId(), this);
		}
		/**
		 * Set the category of the receiver.
		 * 
		 * @param category
		 */
		public void setCategory(MarkerCategory category) {
			this.category = category;
		}
		/**
		 * Get the category for the receiver.
		 *