+ // We use ::value() here instead of the [] operator because the latter has the side-effect
+ // of automatically inserting a null value with the passed key into the map. See
+ // https://doc.qt.io/qt-5/qhash.html#operator-5b-5d and https://doc.qt.io/qt-5/qhash.html#value.
+ return _peerMap.value(peerId);