A helper function to reduce the number of nested loops.
        

        Yields
        -------
        (dynamic_ex) or (static_ex)
            Yields the exercises in the program.

def _yield_exercises(self):
        """A helper function to reduce the number of nested loops.
        

        Yields
        -------
        (dynamic_ex) or (static_ex)
            Yields the exercises in the program.

        """
        for day in self.days:
            for dynamic_ex in day.dynamic_exercises:
                yield dynamic_ex
            for static_ex in day.static_exercises:
                yield static_ex