code: def comment(line: str) -> str:
      """Return comment header line."""
      return f"// {line}\n"
  
imports: import contextlib
  import typing
  from .None import _tools
  from .None import base
  from .None import quoting
label_desc: Use image node_id 1 for calling a global function with example usage: comment(line) and returns: str, line, str