private void flush(int storeFilessize) throws IOException {
    flushStore(store, id++);
    assertEquals(storeFilessize, this.store.getStorefiles().size());
    assertEquals(0, ((AbstractMemStore) this.store.memstore).getActive().getCellsCount());
  }
Getting data from memstore and files
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHStore.java