def _checksum(cls, line):
        """Compute the checksum of a full line

        Args:
            line (str): Line to compute the checksum from
        Return:
            int: Checksum (modulo 10)
        """
        tr_table = str.maketrans({c: None for c in ascii_uppercase + "+ ."})
        no_letters = line[:68].translate(tr_table).replace("-", "1")
        return sum([int(l) for l in no_letters]) % 10
Compute the checksum of a full line

        Args:
            line (str): Line to compute the checksum from
        Return:
            int: Checksum (modulo 10)