xbt_assert(linkUp, "Link '%s' not found!", hostlink->link_up.c_str());
xbt_assert(linkDown, "Link '%s' not found!", hostlink->link_down.c_str());
xbt_assert(linkUp, "Link '%s' not found!", hostlink->link_up.c_str());
xbt_assert(linkDown, "Link '%s' not found!", hostlink->link_down.c_str());