added original methods closure() and closureStar back in for backward…

… compatibility

src/main/java/io/usethesource/vallang/IRelation.java

@@ -79,6 +79,14 @@ public default C compose(IRelation<C> that) {
         return w.done();
     }   
 
+    /**
+     * @return the transitive non-reflexive closure of a binary relation
+     * @throws UnsupportedOperationException when the receiver is not a binary relation
+     */
+    public default C closure() {
+        return closure(false);
+    }
+
     /**
      * @return the transitive non-reflexive closure of a binary relation
      * @param forceDepthFirst chooses the DFS algorithm over the BFS algorithm even though the size is small
@@ -100,6 +108,14 @@ public default C closure(boolean forceDepthFirst) {
         return next;
     }
 
+    /**
+     * @return the transitive non-reflexive closure of a binary relation
+     * @throws UnsupportedOperationException when the receiver is not a binary relation
+     */
+    public default C closureStar() {
+        return closureStar(false);
+    }
+
     /**
      * @return the transitive reflexive closure of a binary relation
      * @param forceDepthFirst chooses the DFS algorithm over the BFS algorithm even though the size is small