(name, start, count, last_values)
Generate the next value when not given.

        name: the name of the member
        start: the initial start value or None
        count: the number of existing members
        last_value: the last value assigned or None
Generate the next value when not given.
Generate the next value when not given .
def _generate_next_value_(name, start, count, last_values):
        """
        Generate the next value when not given.

        name: the name of the member
        start: the initial start value or None
        count: the number of existing members
        last_value: the last value assigned or None
        """
        for last_value in reversed(last_values):
            try:
                return last_value + 1
            except TypeError:
                pass
        else:
            return start
def _generate_next_value_ ( name , start , count , last_values ) : for last_value in reversed ( last_values ) : try : return last_value + 1 except TypeError : pass else : return start