@Override
  public PosixFileAttributes readAttributes(File file) {
    return new Attributes(file);
  }
@Test
  public void testAttributes() {
    PosixFileAttributes attrs = provider.readAttributes(file);
    assertThat(attrs.permissions()).isEqualTo(PosixFilePermissions.fromString("rw-r--r--"));
    assertThat(attrs.group()).isEqualTo(createGroupPrincipal("group"));
    assertThat(attrs.fileKey()).isEqualTo(0);
  }