### Question:
Configuration { public static Configuration osX() { return OsxHolder.OS_X; } 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 testFileSystemForDefaultOsXConfiguration() throws IOException { FileSystem fs = Jimfs.newFileSystem(Configuration.osX()); 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")); try { Files.createFile(fs.getPath("/FOO")); fail(); } catch (FileAlreadyExistsException expected) { } }