Node: streamParents(): added

src/main/java/net/kemitix/node/Node.java

@@ -250,4 +250,11 @@ public interface Node<T> {
      * @return a stream of all the nodes in the tree below this node
      */
     Stream<Node<T>> streamAll();
+
+    /**
+     * Returns a stream of all the node's ancestor nodes.
+     *
+     * @return a stream of the node's parents recursively until the root node
+     */
+    Stream<Node<T>> streamParents();
 }

src/main/java/net/kemitix/node/NodeItem.java

@@ -375,4 +375,10 @@ class NodeItem<T> implements Node<T> {
         return Stream.concat(Stream.of(this), getChildren().stream()
                                                            .flatMap(Node::streamAll));
     }
+
+    @Override
+    public Stream<Node<T>> streamParents() {
+        return getParent().map(node -> Stream.concat(Stream.of(node), node.streamParents()))
+                          .orElseGet(Stream::empty);
+    }
 }