code: def set_env_for_DeepRec():
      """
      Set some ENV for these DeepRec's features enabled by ENV.
      More Detail information is shown in
      https://deeprec.readthedocs.io/zh/latest/index.html.
      START_STATISTIC_STEP & STOP_STATISTIC_STEP:
          On CPU platform, DeepRec supports memory optimization
          in both stand-alone and distributed training. It's default to open, and the
          default start and stop steps of collection is 1000 and 1100. Reduce the initial
          cold start time by the following settings.
      MALLOC_CONF: On CPU platform, DeepRec can use memory optimization with the jemalloc library.
          Please preload libjemalloc.so by `LD_PRELOAD=./libjemalloc.so.2 python ...`
      """
      os.environ["START_STATISTIC_STEP"] = "100"
      os.environ["STOP_STATISTIC_STEP"] = "110"
      os.environ[
          "MALLOC_CONF"
      ] = "background_thread:true,metadata_thp:auto,dirty_decay_ms:20000,muzzy_decay_ms:20000"
  
imports: import time
  import argparse
  import tensorflow
  import os
  import sys
  import math
  import collections
  from tensorflow.python.client import timeline
  import json
  from tensorflow.python.ops import partitioned_variables
  import ray
  from bigdl.dllib.utils.log4Error import *
  from bigdl.orca import init_orca_context, stop_orca_context, OrcaContext
  from bigdl.orca.data.utils import process_spark_xshards
  from bigdl.orca.learn.utils import maybe_dataframe_to_xshards
  from bigdl.friesian.feature import FeatureTable
label_desc: Use image node_id 7 for calling a global function with example usage: set_env_for_DeepRec() without return types