<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_version_rank(version):
 """ Converts a version string to it's rank. Usage:: 4002008000000 4000000000000 <type 'int'> :param version: Current version to calculate rank. :type version: unicode :return: Rank. :rtype: int """


    tokens = list(foundations.common.unpack_default(filter(any, re.split("\.|-|,", version)), length=4, default=0))
    rank = sum((int(1000 ** i) * int(tokens[-i]) for i in range(len(tokens), 0, -1)))
    LOGGER.debug("> Rank: '{0}'.".format(rank))
    return rank