There are some potential feefilter cleanups mentioned and motivated in comment https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-805808485 . If you address the locking one, please be careful and make sure that `round()` is only called under a lock. See https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-807992199

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{
    InterruptHTTPServer();
    InterruptHTTPRPC();
    InterruptRPC();
    InterruptREST();
    InterruptTorControl();
    InterruptMapPort();
    if (node.connman)
        node.connman->Interrupt();
    if (g_txindex) {
        g_txindex->Interrupt();
    }
    ForEachBlockFilterIndex([](BlockFilterIndex& index) { index.Interrupt(); });
    if (g_coin_stats_index) {
        g_coin_stats_index->Interrupt();
    }
}
void Shutdown(NodeContext& node)