code: def test_recordio(tmpdir):
      frec = tmpdir.join("rec")
      N = 255
  
      writer = mx.recordio.MXRecordIO(str(frec), "w")
      for i in range(N):
          writer.write(bytes(str(chr(i)), "utf-8"))
      del writer
  
      reader = mx.recordio.MXRecordIO(str(frec), "r")
      for i in range(N):
          res = reader.read()
          assert res == bytes(str(chr(i)), "utf-8")
  
imports: import sys
  import mxnet
  import numpy
  import random
  import string
label_desc: Use image node_id 1 for calling a global function with example usage: test_recordio(tmpdir) without return types