VirtualFile o3 = o2.getChild("level3.zip");
VirtualFile l3 = l2.getChild("level3.zip");
assertFalse(l3.isLeaf());
assertEquals(o3.toURL(), l3.toURL());
assertEquals(getProtocol() + urlString + "level1.zip/level2.zip/level3.zip/", l3.toURL().toExternalForm());
VirtualFile o3sub = o3.getChild("test3.txt");
VirtualFile l3sub = l3.getChild("test3.txt");
assertTrue(l3sub.isLeaf());
assertEquals(o3sub.toURL(), l3sub.toURL());