isLanguageSpecific should return false, if different domains are

registered only one can be validated otherwise

plugins/org.yakindu.sct.model.stext/src/org/yakindu/sct/model/stext/validation/STextJavaValidator.java

@@ -811,11 +811,17 @@ public class STextJavaValidator extends AbstractSTextJavaValidator implements ST
 		if (!isResponsible)
 			return false;
 		Statechart statechart = getStatechart(eObject);
+		if(statechart == null)
+			return false;
 		if (domainID == null || !domainID.equals(statechart.getDomainID())) {
 			return false;
 		}
 		return true;
 	}
+	@Override
+	public boolean isLanguageSpecific() {
+		return false;
+	}
 
 	protected Statechart getStatechart(EObject context) {
 		final ContextElementAdapter provider = (ContextElementAdapter) EcoreUtil.getExistingAdapter(context.eResource(),