// dot -Tpng -o /tmp/h.png < docs/hierarchy.dot
digraph D {
    "net::sup" -> "http::sup";
    "net::sup" -> "registry";
    "http::sup" -> "http::actor";
    "http::sup" -> "https::actor";
    "http::sup" -> "registry" [style = "dotted"];
    "net::sup" -> "local_announcer::actor";
    "net::sup" -> "global_announcer::sup";
    "net::sup" -> "acceptor::actor";
    "acceptor::actor" -> "registry" [style = "dotted"];
    "global_announcer::sup" -> "ssdp::actor";
    "global_announcer::sup" -> "registry" [style = "dotted"];
    "global_announcer::sup" -> "http::sup" [style = "dotted"];
    "global_announcer::sup" -> "acceptor::actor" [style = "dotted"];
    "local_announcer::actor" -> "registry" [style = "dotted"];
    "local_announcer::actor" -> "acceptor::actor" [style = "dotted"];
}
