Make html lists print a nice toString method.

tests/html/node_test.dart

Index: tests/html/node_test.dart
diff --git a/tests/html/node_test.dart b/tests/html/node_test.dart
index 7b4b17dbbbf8bc95807d8fd1b5ad287ec4dd033f..598899d56109d49fbb206017fc0f7bb8ddd456f3 100644
--- a/tests/html/node_test.dart
+++ b/tests/html/node_test.dart
@@ -26,6 +26,16 @@ main() {
       predicate((x) => x is InputElement, 'is an InputElement');
 
   group('functional', () {
+    test('toString', () {
+      final nodes = makeNodeWithChildren();
+      // TODO(efortuna): Update this test when you have actual toString methods
+      // for the items in the node List as well.
+      expect(nodes.nodes.toString(), "[Instance of 'Text', BR, "
+          "Instance of 'Comment']");
+      final node = makeNode();
+      expect(node.nodes.toString(), '[]');
+    });
+
     test('replaceWith', () {
       final node = makeNodeWithChildren();
       final subnode = node.nodes[1];