code: def encode(key: bytes, value: bytes):
      size = struct.pack(">Q", len(key))
      return (size + key + value).hex()
  
imports: import logging
  import struct
  import typing
  from typing import Callable, Iterable, Tuple, Optional, Any
  import pyspark
  from pyspark.rddsampler import RDDSamplerBase
  from fate.arch import URI
  from fate.arch.computing.api import KVTable, ComputingEngine, K, V
  from fate.arch.computing.api._table import _lifted_reduce_to_serdes, get_serdes_by_type
  from ._materialize import materialize, unmaterialize
label_desc: Use image node_id 1 for calling the HDFSCoder obj's underlying member method code with example usage: obj.encode(key, value) and returns: unknown