small fix

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/extension/data/PrototypeCategory.java

@@ -79,4 +79,10 @@ public class PrototypeCategory {
 	public PrototypeCategory getParentCategory() {
 		return parentCategory;
 	}
+
+	/** {@inheritDoc} */
+	@Override
+	public String toString() {
+		return "Prototype category: " + categoryName;
+	}
 }