code: def extras_string(extras: List[str]) -> str:
      """Returns the argument passed to `pip install` to install a project from its
      setup.py and target a specific set of extras_require dependencies.
  
        Args:
            extras: (potentially empty) list of extra_requires deps.
      """
      ret = "."
      if len(extras) > 0:
          ret += "[{}]".format(",".join(extras))
      return ret
  
imports: from __future__ import absolute_import, division, print_function
  import json
  import os
  import subprocess
  import tempfile
  from enum import Enum
  from pathlib import Path
  from typing import Any, Dict, List, NamedTuple, NewType, Optional, Union
  from absl import logging
  from blessings import Terminal
  import caliban.config
  import caliban.util
  import caliban.util.fs
  import caliban.util.metrics
label_desc: Use image node_id 10 for calling a global function with example usage: extras_string(extras) and returns: ret