Add the impact severity for the most severe consequence
        
            Args:
                variant_obj (puzzle.models.Variant)

def _add_impact_severity(self, variant_obj):
        """Add the impact severity for the most severe consequence
        
            Args:
                variant_obj (puzzle.models.Variant)
        
        """
        if variant_obj.most_severe_consequence:
            variant_obj.impact_severity = IMPACT_SEVERITIES.get(
                variant_obj.most_severe_consequence
            )