code: def version(self) -> int:
          
          version = self._config.get('version', 1)
  
          if version not in SUPPORTED_SCENARIO_VERSIONS:
              raise InvalidScenarioVersion(f'Unexpected scenario version {version}')
          return version
docs: Return the scenario's version.
  
          If this is not present, we default to version 1.
  
          :raises InvalidScenarioVersion:
              if the supplied version is not present in :var:`SUPPORTED_SCENARIO_VERSIONS`.