### Question:
PosixAttributeProvider extends AttributeProvider { @Override public PosixFileAttributeView view( FileLookup lookup, ImmutableMap<String, FileAttributeView> inheritedViews) { return new View( lookup, (BasicFileAttributeView) inheritedViews.get("basic"), (FileOwnerAttributeView) inheritedViews.get("owner")); }  @Override String name(); @Override ImmutableSet<String> inherits(); @Override ImmutableSet<String> fixedAttributes(); @SuppressWarnings("unchecked") @Override ImmutableMap<String, ?> defaultValues(Map<String, ?> userProvidedDefaults); @NullableDecl @Override Object get(File file, String attribute); @Override void set(File file, String view, String attribute, Object value, boolean create); @Override Class<PosixFileAttributeView> viewType(); @Override PosixFileAttributeView view(
      FileLookup lookup, ImmutableMap<String, FileAttributeView> inheritedViews); @Override Class<PosixFileAttributes> attributesType(); @Override PosixFileAttributes readAttributes(File file);  }### Answer:
@Test public void testView() throws IOException { file.setAttribute("owner", "owner", createUserPrincipal("user")); PosixFileAttributeView view = provider.view( fileLookup(), ImmutableMap.of( "basic", new BasicAttributeProvider().view(fileLookup(), NO_INHERITED_VIEWS), "owner", new OwnerAttributeProvider().view(fileLookup(), NO_INHERITED_VIEWS))); assertNotNull(view); assertThat(view.name()).isEqualTo("posix"); assertThat(view.getOwner()).isEqualTo(createUserPrincipal("user")); PosixFileAttributes attrs = view.readAttributes(); assertThat(attrs.fileKey()).isEqualTo(0); assertThat(attrs.owner()).isEqualTo(createUserPrincipal("user")); assertThat(attrs.group()).isEqualTo(createGroupPrincipal("group")); assertThat(attrs.permissions()).isEqualTo(PosixFilePermissions.fromString("rw-r--r--")); view.setOwner(createUserPrincipal("root")); assertThat(view.getOwner()).isEqualTo(createUserPrincipal("root")); assertThat(file.getAttribute("owner", "owner")).isEqualTo(createUserPrincipal("root")); view.setGroup(createGroupPrincipal("root")); assertThat(view.readAttributes().group()).isEqualTo(createGroupPrincipal("root")); assertThat(file.getAttribute("posix", "group")).isEqualTo(createGroupPrincipal("root")); view.setPermissions(PosixFilePermissions.fromString("rwx------")); assertThat(view.readAttributes().permissions()) .isEqualTo(PosixFilePermissions.fromString("rwx------")); assertThat(file.getAttribute("posix", "permissions")) .isEqualTo(PosixFilePermissions.fromString("rwx------")); }