public void test_NodeRO_isLeaf() {
map = c.newMap();
final Node root = map.getRoot();
assertTrue("even root is a leaf, if single", root.isLeaf());
root.createChild("child");
assertFalse("root is never a leaf, even without children", root.isLeaf());
assertTrue("child without children should be leaf", firstChild(root).isLeaf());
firstChild(root).createChild("grandchild");
assertFalse("child with children is not a leaf", firstChild(root).isLeaf());
}