code: def get_docker_tag(platform: str, registry: str) -> str:
      """:return: docker tag to be used for the container"""
      with open("docker/docker-compose.yml", "r") as f:
          compose_config = yaml.load(f.read(), yaml.SafeLoader)
          return compose_config["services"][platform]["image"].replace(
              "${DOCKER_CACHE_REGISTRY}", registry
          )
  
file_path: mxnet/ci/build.py
imports: import argparse
  import pprint
  import os
  import signal
  import subprocess
  from itertools import chain
  from subprocess import check_call
  from typing import *
  import yaml
  from util import *
label_desc: Use image node_id 2 for calling a global function with example usage: get_docker_tag(platform, registry) and returns: compose_config