code: def test_str8():
      header = b"\xd9"
      data = b"x" * 32
      b = packb(data.decode(), use_bin_type=True)
      assert len(b) == len(data) + 2
      assert b[0:2] == header + b"\x20"
      assert b[2:] == data
      assert unpackb(b) == data
  
      data = b"x" * 255
      b = packb(data.decode(), use_bin_type=True)
      assert len(b) == len(data) + 2
      assert b[0:2] == header + b"\xff"
      assert b[2:] == data
      assert unpackb(b) == data
  
imports: from pandas.io.msgpack import ExtType, packb, unpackb
label_desc: Use image node_id 1 for calling a global function with example usage: test_str8() without return types