Return the subclass of ScfCycle associated to the task or
        None if no SCF algorithm if associated to the task.

def cycle_class(self):
        """
        Return the subclass of ScfCycle associated to the task or
        None if no SCF algorithm if associated to the task.
        """
        if isinstance(self, RelaxTask):
            return abiinspect.Relaxation
        elif isinstance(self, GsTask):
            return abiinspect.GroundStateScfCycle
        elif self.is_dfpt_task:
            return abiinspect.D2DEScfCycle

        return None