### Question:
ZkPath { public static List<String> filterOutHiddenPaths(List<String> paths) { List<String> pathsNonHidden = new ArrayList<String>(paths.size()); for (String path : paths) { if (!ZkPath.isHidden(path)) { pathsNonHidden.add(path); } } return pathsNonHidden; }  static String append(String... parts); static String getFilename(String path); static boolean isHidden(String path); static List<String> filterOutHiddenPaths(List<String> paths);  }### Answer:
@Test public void testFilterOutHiddenPaths() { List<String> paths = new ArrayList<String>(); String p1 = "/a/b"; String p2 = "/a/b/c"; String p3 = "/a/b/.c"; String p4 = "/a/..c"; paths.add(p1); paths.add(p2); paths.add(p3); paths.add(p4); List<String> notHiddenPaths = ZkPath.filterOutHiddenPaths(paths); assertEquals(2, notHiddenPaths.size()); assertEquals(true, notHiddenPaths.contains(p1)); assertEquals(true, notHiddenPaths.contains(p2)); assertEquals(false, notHiddenPaths.contains(p3)); assertEquals(false, notHiddenPaths.contains(p4)); }