class_docstr: ModelService wraps up all preprocessing, inference and postprocessing
  functions used by model service. It is defined in a flexible manner to
  be easily extended to support different frameworks.
class_docstr_tok: ["ModelService","wraps","up","all","preprocessing",",","inference","and","postprocessing","functions","used","by","model","service",".","It","is","defined","in","a","flexible","manner","to","be","easily","extended","to","support","different","frameworks","."]
docstr: Internal initialize ModelService.
  
  :param context: MMS context object
  :return:
docstr_tok: ["Internal","initialize","ModelService",".",":","param","context",":","MMS","context","object",":","return",":"]
code: def initialize(self, context):
      """
      Internal initialize ModelService.
  
      :param context: MMS context object
      :return:
      """
      self._context = context
      properties = context.system_properties
      model_dir = properties.get("model_dir")
  
      signature_file_path = os.path.join(
          model_dir, context.manifest["Model"]["Signature"]
      )
      if not os.path.isfile(signature_file_path):
          raise ValueError("Signature file is not found.")
  
      with open(signature_file_path) as f:
          self._signature = json.load(f)
  
file_path: serve/ts/model_service/model_service.py
imports: import ast
  import json
  import logging
  import os
  import time
  from abc import ABCMeta, abstractmethod
label_desc: Use image node_id 2 for calling the ModelService obj's underlying member method code with example usage: obj.initialize(context) without return types