@classmethod<EOL><INDENT>def _is_flag(cls, arg):<DEDENT>
if arg == '<STR_LIT>':<EOL><INDENT>return False<EOL><DEDENT>if not arg.startswith('<STR_LIT:->'):<EOL><INDENT>return False<EOL><DEDENT>if arg.startswith('<STR_LIT>'):<EOL><INDENT>first_char = arg[<NUM_LIT:2>]<EOL><DEDENT>else:<EOL><INDENT>first_char = arg[<NUM_LIT:1>]<EOL><DEDENT>if not first_char.isalpha():<EOL><INDENT>return False<EOL><DEDENT>return True<EOL>
Check if an argument is a flag.

        A flag starts with - or -- and the next character must be a letter
        followed by letters, numbers, - or _.  Currently we only check the
        alpha'ness of the first non-dash character to make sure we're not just
        looking at a negative number.

        Returns:
            bool: Whether the argument is a flag.