code: def extend_log(self, field, value):
          
          self.__log_extensions.append((field, value))
          try:
              yield
          except Exception as e:
              setattr(e, "workflows_log_" + field, value)
              raise
          finally:
              self.__log_extensions.remove((field, value))
docs: A context wherein a specified extra field in log messages is populated
          with a fixed value. This affects all log messages within the context.