@Override
    public void enterNode(String name) {
        stringBuilder.append(prefixes.pop());
        prefixes.push(", ");
        stringBuilder.append(name).append("(");
        prefixes.push("");
    }
@Test
    public void testEnterNode() {
        NodeStringifier stringifier = new NodeStringifier();
        stringifier.enterNode("foo");
        stringifier.leaveNode();
        assertEquals("foo()", stringifier.toString());
    }