code: def load_config():
      try:
          with open("ppml-conf.yaml", "r") as stream:
              conf = yaml.safe_load(stream)
              if "privateKeyFilePath" in conf:
                  FLClient.secure = True
                  with open(conf["privateKeyFilePath"], "rb") as f:
                      FLClient.creds = grpc.ssl_channel_credentials(
                          f.read()
                      )
      except yaml.YAMLError as e:
          logging.warn("Loading config failed, using default config ")
      except Exception as e:
          logging.warn(
              'Failed to find config file "ppml-conf.yaml", using default config'
          )
  
file_path: BigDL/python/ppml/src/bigdl/ppml/fl/nn/fl_client.py
imports: import logging
  import grpc
  from bigdl.ppml.fl.nn.generated.nn_service_pb2 import TrainRequest, PredictRequest, UploadMetaRequest
  from bigdl.ppml.fl.nn.generated.nn_service_pb2_grpc import *
  import yaml
  import threading
  from bigdl.dllib.utils.log4Error import invalidInputError
label_desc: Use image node_id 4 for calling the FLClient obj's underlying member method code with example usage: obj.load_config() without return types