@Test
public void testMemberOverwriteDenies() {

    PermissionSet base = PermissionSet.of(SEND_MESSAGES);
    List<PermissionOverwrite> roleOverwrites = Collections.emptyList();
    PermissionOverwrite memberOverwrite = overwrite(PermissionSet.none(), PermissionSet.of(SEND_MESSAGES));
    PermissionSet actual = PermissionUtil.computePermissions(base, null, roleOverwrites, memberOverwrite);
    PermissionSet expected = PermissionSet.none();
    assertEquals(expected, actual);
}