code: def bulk_record_workunits(self, engine_workunits):
      
      for workunit in engine_workunits:
        duration = workunit['end_timestamp'] - workunit['start_timestamp']
  
        span = zipkin_span(
          service_name="pants",
          span_name=workunit['name'],
          duration=duration,
          span_storage=self.span_storage,
        )
        span.zipkin_attrs = ZipkinAttrs(
          trace_id=self.trace_id,
          span_id=workunit['span_id'],
          # TODO change it when we properly pass parent_id to the v2 engine Nodes
          # TODO Pass parent_id with ExecutionRequest when v2 engine is called by a workunit
          # TODO pass parent_id when v2 engine Node is called by another v2 engine Node
          parent_span_id=workunit.get("parent_id", self.parent_id),
          flags='0', # flags: stores flags header. Currently unused
          is_sampled=True,
        )
        span.start()
        span.start_timestamp = workunit['start_timestamp']
        span.stop()
docs: A collection of workunits from v2 engine part