static void
sks_cont_next (void *cls, const struct GNUNET_FS_Uri *uri, const char *emsg)
{
  GNUNET_assert (NULL == emsg);
  err += 2;
  GNUNET_FS_namespace_list_updateable (ns, NULL, &check_this_next, NULL);
}
static void
sks_cont_this (void *cls, const struct GNUNET_FS_Uri *uri, const char *emsg)
{
    GNUNET_assert (NULL == emsg);
    err = 1;
    GNUNET_FS_namespace_list_updateable (fs, ns, NULL, &check_this, NULL);
    GNUNET_FS_publish_sks (fs, ns, "next", "future", meta, uri_next, &bo,
                           GNUNET_FS_PUBLISH_OPTION_NONE, &sks_cont_next, NULL);

}
static void
check_this_next (void *cls, const char *last_id,
                 const struct GNUNET_FS_Uri *last_uri,
                 const struct GNUNET_CONTAINER_MetaData *last_meta,
                 const char *next_id)
{
    GNUNET_break (0 == strcmp (last_id, "this"));
    GNUNET_break (0 == strcmp (next_id, "next"));
    err -= 2;
    err += 4;
    GNUNET_FS_namespace_list_updateable (fs, ns, next_id, &check_next, NULL);
}