### Question:
Directory extends File implements Iterable<DirectoryEntry> { @NullableDecl public DirectoryEntry get(Name name) { int index = bucketIndex(name, table.length); DirectoryEntry entry = table[index]; while (entry != null) { if (name.equals(entry.name())) { return entry; } entry = entry.next; } return null; } private  Directory(int id); private  Directory(int id, Name rootName); static Directory create(int id); static Directory createRoot(int id, Name name); DirectoryEntry entryInParent(); Directory parent(); boolean isEmpty(); @NullableDecl DirectoryEntry get(Name name); void link(Name name, File file); void unlink(Name name); ImmutableSortedSet<Name> snapshot(); @Override Iterator<DirectoryEntry> iterator();  }### Answer:
@Test public void testGet() { assertThat(root.get(Name.simple("foo"))).isEqualTo(entry(root, "foo", dir)); assertThat(dir.get(Name.simple("foo"))).isNull(); assertThat(root.get(Name.simple("Foo"))).isNull(); }