code: def _create_build_step(spec: ImageSpec) -> BuildStep:
      args = ["build"]
      args += ["-t", spec.tag]
      args += ["-f", spec.dockerfile]
  
      for k, v in spec.build_args.items():
          args.append("--build-arg")
          args.append(f"{k}={v}")
      args.append(".")
  
      if spec.image_type == ImageType.GPU:
          dependencies = [spec.build_args["BASE_IMAGE"]]
      else:
          dependencies = ["-"]
  
      return BuildStep(
          step_id=spec.tag, args=args, dependencies=dependencies
      )
  
imports: from absl import flags, app, logging
  from copy import copy
  from typing import Dict, List, Any, NamedTuple, Optional, Set
  from enum import Enum
  import json
  import pprint
label_desc: Use image node_id 8 for calling a global function with example usage: _create_build_step(spec) and returns: BuildStep