code: def empty(
      self,
      docs: DocumentArray,
      tracing_context: Optional[Context],
      **kwargs,
  ):
      if self.request_counter:
          self.request_counter.add(1)
  
      if self.tracer:
          with self.tracer.start_span(
              "dummy", context=tracing_context
          ) as span:
              span.set_attribute("len_docs", len(docs))
              return docs
      else:
          return docs
  
imports: from typing import Dict, Optional
  import requests
  from docarray import DocumentArray
  from opentelemetry.context.context import Context
  from prometheus_api_client import PrometheusConnect
  from jina import Executor, requests
label_desc: Use image node_id 2 for calling the ExecutorTestWithTracing obj's underlying member method code with example usage: obj.empty(docs, tracing_context) and returns: docs, docs