code: def roundtrip(obj):
      """roundtrip an object through serialization"""
      bufs = serialize_object(obj)
      obj2, remainder = deserialize_object(bufs)
      assert remainder == []
      return obj2
  
imports: import pickle
  from collections import namedtuple
  import pytest
  from ipyparallel import interactive
  from ipyparallel.serialize import deserialize_object, serialize_object
  from ipyparallel.serialize.canning import CannedArray, CannedClass
label_desc: Use image node_id 1 for calling a global function with example usage: roundtrip(obj) and returns: obj2