def METHOD_NAME(self, decision_ref, node):
    if decision_ref not in self.dmn_parsers:
        options = ', '.join(list(self.dmn_parsers.keys()))
        raise ValidationException(
            'No DMN Diagram available with id "%s", Available DMN ids are: %s' %(decision_ref, options),
            node=node, file_name='')
    dmn_parser = self.dmn_parsers[decision_ref]
    dmn_parser.parse()
    decision = dmn_parser.decision
    return DMNEngine(decision.decisionTables[0])