code: def postprocess_variants_command(
      ref: str, infile: str, outfile: str, extra_args: str, **kwargs
  ) -> Tuple[str, Optional[str]]:
      """Returns a postprocess_variants (command, logfile) for subprocess."""
      cpus = _POSTPROCESS_CPUS.value
      if not cpus:
          cpus = _NUM_SHARDS.value
      command = ["time", "/opt/deepvariant/bin/postprocess_variants"]
      command.extend(["--ref", '"{}"'.format(ref)])
      command.extend(["--infile", '"{}"'.format(infile)])
      command.extend(["--outfile", '"{}"'.format(outfile)])
      command.extend(["--cpus", '"{}"'.format(cpus)])
      # Extend the command with all items in kwargs and extra_args.
      kwargs = _update_kwargs_with_warning(
          kwargs, _extra_args_to_dict(extra_args)
      )
      command = _extend_command_by_args_dict(command, kwargs)
      logfile = None
      if _LOGGING_DIR.value:
          logfile = "{}/postprocess_variants.log".format(
              _LOGGING_DIR.value
          )
      return (" ".join(command), logfile)
  
imports: import os
  import subprocess
  import sys
  import tempfile
  from typing import Any, Dict, Optional, Tuple
  from absl import app
  from absl import flags
  from absl import logging
  import tensorflow
label_desc: Use image node_id 9 for calling a global function with example usage: postprocess_variants_command(ref, infile, outfile, extra_args) and returns: str,  logfile