code: def _output(calls, args):
      
      # Sort the keys appropriately
      if args.natural_sort or args.source:
          calls = sorted(calls, key=lambda c: (c.filename, c.lineno))
      else:
          calls = sorted(calls, key=lambda c: c.key)
  
      out = []
  
      # Handle displaying only the list of keys
      if args.only_keys:
          keys = set()
          for call in calls:
              if call.key in keys:
                  continue
              out.append(_format_call(call, args))
              keys.add(call.key)
  
          out = '\n'.join(out)
          if args.color:
              out = _colorize(out)
          print(out, end=' ')
  
          # We're done here
          return
  
      # Build a list of keys which have default values available, so that we can
      # toggle between displaying only those keys with defaults and all keys
      keys = set()
      for call in calls:
          if call.default:
              keys.add(call.key)
  
      for call in calls:
          if not args.all and not call.default and call.key in keys:
              continue
          out.append(_format_call(call, args))
  
      out = '\n'.join(out)
      if args.color:
          out = _colorize(out)
      print(out, end=' ')
docs: Outputs `calls`.
  
      :param calls: List of :class:`_PyconfigCall` instances
      :param args: :class:`~argparse.ArgumentParser` instance
      :type calls: list
      :type args: argparse.ArgumentParser