public void setRegionReplicationSink(RegionReplicationSink regionReplicationSink) {
      this.regionReplicationSink = Optional.of(regionReplicationSink);
    }
The {@link RegionReplicationSink#failedReplicas} is cleared by the
{@link FlushAction#CANNOT_FLUSH} marker.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/regionreplication/TestRegionReplicationForFlushMarker.java