docs: def get_flag_args(**options):
      """Build a list of flags."""
      flags = []
      for key, value in options.items():
          # Build short flags.
          if len(key) == 1:
              flag = f'-{key}'
          # Built long flags.
          else:
              flag = f'--{key}'
          flags = flags + [flag, value]
      return flags