@Override
  public long heapSize() {
    MemStoreSize memstoreSize = this.memstore.size();
    return DEEP_OVERHEAD + memstoreSize.getHeapSize() + storeContext.heapSize();
  }
Used for tests.
@return cache configuration for this Store.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java