public boolean isTombstoneTooOld(T mbr, long gcVersion) {
    Long newestReapedVersion;
    if (mbr == null || mbr.equals(myId)) {
      newestReapedVersion = localGCVersion.get();
    } else {
      newestReapedVersion = memberToGCVersion.get(mbr);
    }
    if (newestReapedVersion != null) {
      return (newestReapedVersion >= gcVersion);
    }
    return false;
  }
returns true if tombstones newer than the given version have already been reaped. This means
that a clear or GC has been received that should have wiped out the operation this version
stamp represents, but this operation had not yet been received

@return true if the given version should be rejected
geode-core/src/main/java/org/apache/geode/internal/cache/versions/RegionVersionVector.java