docstr: empty stdout/err are not displayed (groupby type)
docstr_tok: ["empty","stdout\/err","are","not","displayed","(","groupby","type",")"]
code: def test_display_empty_streams_type(self):
      """empty stdout/err are not displayed (groupby type)"""
      self.minimum_engines(1)
  
      v = self.client[:]
      ar = v.execute("print (5555)")
      ar.get(5)
      with capture_output() as io:
          ar.display_outputs()
      assert io.stderr == ""
      assert io.stdout.count("5555"), len(v) == io.stdout
      assert not "\n\n" in io.stdout, io.stdout
      assert io.stdout.count("[stdout:"), len(v) == io.stdout
  
      ar = v.execute("a=5")
      ar.get(5)
      with capture_output() as io:
          ar.display_outputs()
      assert io.stderr == ""
      assert io.stdout == ""
  
imports: import os
  import time
  from datetime import datetime
  import pytest
  from IPython.utils.io import capture_output
  import ipyparallel
  from ipyparallel import error
  from .clienttest import ClusterTestCase, raises_remote
label_desc: Use image node_id 24 for calling the TestAsyncResult obj's underlying member method code with example usage: obj.test_display_empty_streams_type() without return types