default void preCompactScannerOpen(ObserverContext<? extends RegionCoprocessorEnvironment> c,
    Store store, ScanType scanType, ScanOptions options, CompactionLifeCycleTracker tracker,
    CompactionRequest request) throws IOException {
  }
Called before we open store scanner for compaction. You can use the {@code options} to change
max versions and TTL for the scanner being opened.
@param c        the environment provided by the region server
@param store    the store being compacted
@param scanType type of Scan
@param options  used to change max versions and TTL for the scanner being opened
@param tracker  tracker used to track the life cycle of a compaction
@param request  the requested compaction
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/RegionObserver.java