code: def get_evaluation_parameter(self, parameter_name, default_value=None):
          
          if "evaluation_parameters" in self._expectations_config and \
                  parameter_name in self._expectations_config['evaluation_parameters']:
              return self._expectations_config['evaluation_parameters'][parameter_name]
          else:
              return default_value
docs: Get an evaluation parameter value that has been stored in meta.
  
          Args:
              parameter_name (string): The name of the parameter to store.
              default_value (any): The default value to be returned if the parameter is not found.
  
          Returns:
              The current value of the evaluation parameter.