@Override
  protected void configureForRegion(HRegion region) {
    super.configureForRegion(region);
    int familyNumber = region.getTableDescriptor().getColumnFamilyCount();
    if (familyNumber <= 1) {
      // No need to parse and set flush size lower bound if only one family
      // Family number might also be zero in some of our unit test case
      return;
    }
    setFlushSizeLowerBounds(region);
  }
A {@link FlushPolicy} that only flushes store larger a given threshold. If no store is large
enough, then all stores will be flushed.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/FlushAllLargeStoresPolicy.java