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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* Bitcoin protocol messages
* Bitcoin Core P2P design
* Running our unit and functional tests

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#include <interfaces/node.h>
#include <mapport.h>
#include <miner.h>
#include <net.h>
#include <net_permissions.h>
#include <net_processing.h>
#include <netbase.h>
#include <node/blockstorage.h>
#include <node/context.h>
#include <node/ui_interface.h>
#include <policy/feerate.h>
#include <policy/fees.h>
#include <policy/policy.h>
#include <policy/settings.h>
#include <protocol.h>
#include <rpc/blockchain.h>
#include <rpc/register.h>
#include <rpc/server.h>
#include <rpc/util.h>
#include <scheduler.h>
#include <script/sigcache.h>
#include <script/standard.h>
#include <shutdown.h>
#include <sync.h>
#include <timedata.h>
#include <torcontrol.h>
#include <txdb.h>
#include <txmempool.h>
#include <txorphanage.h>
#include <util/asmap.h>