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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 get_version(brain_or_object):
 """Get the version of the current object :param brain_or_object: A single catalog brain or content object :type brain_or_object: ATContentType/DexterityContentType/CatalogBrain :returns: The current version of the object, or None if not available :rtype: int or None """

    obj = get_object(brain_or_object)
    if not is_versionable(obj):
        return None
    return getattr(aq_base(obj), "version_id", 0)