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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def serialize(obj, no_dump=False):
 """ Serialize an object. Returns a dict containing an `_error` property if a MemoryError happens during the object serialization. See #369. :param obj: the object to serialize :type obj: alignak.objects.item.Item | dict | list | str :param no_dump: if True return dict, otherwise return a json :type no_dump: bool :return: dict or json dumps dict with the following structure :: {'__sys_python_module__': "%s.%s" % (o_cls.__module__, o_cls.__name__) 'content' : obj.serialize()} :rtype: dict | str """

    # print("Serialize (%s): %s" % (no_dump, obj))

    if hasattr(obj, "serialize") and isinstance(obj.serialize, collections.Callable):
        o_dict = {
            '__sys_python_module__': "%s.%s" % (obj.__class__.__module__, obj.__class__.__name__),
            'content': obj.serialize()
        }

    elif isinstance(obj, dict):
        o_dict = {}
        for key, value in list(obj.items()):
            o_dict[key] = serialize(value, True)

    elif isinstance(obj, (list, set)):
        o_dict = [serialize(item, True) for item in obj]

    else:
        o_dict = obj

    if no_dump:
        return o_dict

    result = None
    try:
        result = json.dumps(o_dict, ensure_ascii=False)
    except MemoryError:
        return {'_error': 'Not enough memory on this computer to correctly manage Alignak '
                          'objects serialization! '
                          'Sorry for this, please log an issue in the project repository.'}

    return result