def split_command_from_target(bot_username: str, command: (str or None)) ->(str
    , str):
    """
    Determines the command target bot username
    :param bot_username: the username of this bot
    :param command: the command to check
    :return: (the command, the username of the targeted bot)
    """
    target = bot_username
    if command is None or len(command) <= 0:
        return command, target
    if '@' in command:
        command, target = command.split('@', 1)
    return command, target
