tally()

        Records the value of all tracing variables.

def tally(self):
        """
        tally()

        Records the value of all tracing variables.
        """
        if self.verbose > 2:
            print_(self.__name__ + ' tallying.')
        if self._cur_trace_index < self.max_trace_length:
            self.db.tally()

        self._cur_trace_index += 1
        if self.verbose > 2:
            print_(self.__name__ + ' done tallying.')