### Question:
NodeRef implements Bounded, Comparable<NodeRef> { public static String appendChild(String parentTreePath, String childName) { checkNotNull(parentTreePath); checkNotNull(childName); return ROOT.equals(parentTreePath) ? childName : new StringBuilder(parentTreePath) .append(PATH_SEPARATOR).append(childName).toString(); } NodeRef(Node node, String parentPath, ObjectId metadataId); String getParentPath(); Node getNode(); String path(); String name(); ObjectId objectId(); ObjectId getMetadataId(); RevObject.TYPE getType(); @Override boolean equals(Object o); @Override int hashCode(); @Override int compareTo(NodeRef o); @Override String toString(); static @Nullable String parentPath(@Nullable String fullPath); static void checkValidPath(final String path); static @Nullable String nodeFromPath(@Nullable String fullPath); static boolean isDirectChild(String parentPath, String nodePath); static boolean isChild(String parentPath, String nodePath); static List<String> allPathsTo(final String path); static ImmutableList<String> split(final String path); static String appendChild(String parentTreePath, String childName); @Override boolean intersects(Envelope env); @Override void expand(Envelope env); static int depth(String path); static String removeParent(final String parentPath, final String childPath); static final String ROOT; static final char PATH_SEPARATOR; }### Answer:
@Test public void testAppendChild() { String fullString = NodeRef.appendChild("Points", "Points.1"); assertEquals(fullString, "Points/Points.1"); fullString = NodeRef.appendChild("", "refs"); assertEquals(fullString, "refs"); }