def has_triple_quotes(string: str) -> bool:
    """
    Returns:
        True iff @string starts with three quotation characters.
    """
    raw_string = string.lstrip(STRING_PREFIX_CHARS)
    return raw_string[:3] in {'"""', "'''"}

    Returns:
        True iff @string starts with three quotation characters.
    
src/black/strings.py