public Optional<RowData> get(RowData key) throws IOException {
    byte[] keyBytes = serializeKey(key);
    return get(keyBytes);
  }
Retrieve the RowData from guava cache firstly, if value is null, fetch the value from the
rocksDB.

@param key try to find the record via this key.
@throws IOException if serialize the RowData variable <code>key</code> failed.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/lookup/RocksDBRecordState.java