Returns the index for the given `step` name. If no step is given,
        the current step will be used to get the index.

def get_step_index(self, step=None):
        """
        Returns the index for the given `step` name. If no step is given,
        the current step will be used to get the index.
        """
        if step is None:
            step = self.steps.current
        return self.get_form_list().keyOrder.index(step)