code: def pbtxt2json(content: str):
      """
      Convert protocol messages in text format to json format string.
      """
      message = text_format.Parse(content, ModelConfig())
      json_string = json_format.MessageToJson(message)
      return json_string
  
imports: import copy
  import json
  import os
  import random
  import re
  import signal
  import string
  from collections import defaultdict
  from subprocess import Popen
  from subprocess import STDOUT
  import google.protobuf.json_format
  import google.protobuf.text_format
  import psutil
  import requests
  from .proto.model_config_pb2 import ModelConfig
  from visualdl.utils.dir import FASTDEPLOYSERVER_PATH
label_desc: Use image node_id 1 for calling a global function with example usage: pbtxt2json(content) and returns: json_string