explicit: add Model.hasLabel() method

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11162 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/explicit/Model.java

@@ -133,7 +133,10 @@ public interface Model
 	 * Returns an empty set if there are no labels.
 	 */
 	public Set<String> getLabels();
-	
+
+	/** Returns true if a label with the given name is attached to this model */
+	public boolean hasLabel(String name);
+
 	/**
 	 * Get the total number of transitions in the model.
 	 */

prism/src/explicit/ModelExplicit.java

@@ -295,6 +295,12 @@ public abstract class ModelExplicit implements Model
 		return labels.get(name);
 	}
 
+	@Override
+	public boolean hasLabel(String name)
+	{
+		return labels.containsKey(name);
+	}
+
 	@Override
 	public Set<String> getLabels()
 	{

prism/src/explicit/SubNondetModel.java

@@ -198,6 +198,12 @@ public class SubNondetModel implements NondetModel
 		throw new UnsupportedOperationException();
 	}
 
+	@Override
+	public boolean hasLabel(String name)
+	{
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public int getNumTransitions()
 	{