new_contents: try:
      import uio as io
  except ImportError:
      try:
          import io
      except ImportError:
          print('SKIP')
          raise SystemExit
  
  try:
      io.BytesIO
      io.BufferedReader
  except AttributeError:
      print('SKIP')
      raise SystemExit
  
  BUF_SZ = 4
  
  bts = io.BytesIO()
  bts.write(bytes(range(256)))
  bts.seek(0)
  print(bts.getvalue())
  
  buf = io.BufferedReader(bts, BUF_SZ)
  print(bts.seek(0, 1))
  
  print(buf.read(2))
  print(bts.seek(0, 1))
  
  print(buf.read(1))
  print(bts.seek(0, 1))
  
  print(buf.read(2))
  print(bts.seek(0, 1))
  
  print(buf.read(BUF_SZ * 2))
  print(bts.seek(0, 1))
  
subject: Add BufferedReader test.