### Question:
Configuration { public static Configuration unix() { return UnixHolder.UNIX; } private  Configuration(Builder builder); static Configuration unix(); static Configuration osX(); static Configuration windows(); static Configuration forCurrentPlatform(); static Builder builder(PathType pathType); @Override String toString(); Builder toBuilder();  }### Answer:
@Test public void testDefaultUnixConfiguration() { Configuration config = Configuration.unix(); assertThat(config.pathType).isEqualTo(PathType.unix()); assertThat(config.roots).containsExactly("/"); assertThat(config.workingDirectory).isEqualTo("/work"); assertThat(config.nameCanonicalNormalization).isEmpty(); assertThat(config.nameDisplayNormalization).isEmpty(); assertThat(config.pathEqualityUsesCanonicalForm).isFalse(); assertThat(config.blockSize).isEqualTo(8192); assertThat(config.maxSize).isEqualTo(4L * 1024 * 1024 * 1024); assertThat(config.maxCacheSize).isEqualTo(-1); assertThat(config.attributeViews).containsExactly("basic"); assertThat(config.attributeProviders).isEmpty(); assertThat(config.defaultAttributeValues).isEmpty(); }
@Test public void testFileSystemForDefaultUnixConfiguration() throws IOException { FileSystem fs = Jimfs.newFileSystem(Configuration.unix()); assertThat(fs.getRootDirectories()) .containsExactlyElementsIn(ImmutableList.of(fs.getPath("/"))) .inOrder(); assertThatPath(fs.getPath("").toRealPath()).isEqualTo(fs.getPath("/work")); assertThat(Iterables.getOnlyElement(fs.getFileStores()).getTotalSpace()) .isEqualTo(4L * 1024 * 1024 * 1024); assertThat(fs.supportedFileAttributeViews()).containsExactly("basic"); Files.createFile(fs.getPath("/foo")); Files.createFile(fs.getPath("/FOO")); }
@Test public void testFileSystemWithDefaultWatchService() throws IOException { FileSystem fs = Jimfs.newFileSystem(Configuration.unix()); WatchService watchService = fs.newWatchService(); assertThat(watchService).isInstanceOf(PollingWatchService.class); PollingWatchService pollingWatchService = (PollingWatchService) watchService; assertThat(pollingWatchService.interval).isEqualTo(5); assertThat(pollingWatchService.timeUnit).isEqualTo(SECONDS); }