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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 name(topology_file, topology_name=None):
 """ Calculate the name to save the converted topology as using either either a specified name or the directory name of the current project :param str topology_file: Topology filename :param topology_name: Optional topology name (Default: None) :type topology_name: str or None :return: new topology name :rtype: str """

    if topology_name is not None:
        logging.debug('topology name supplied')
        topo_name = topology_name
    else:
        logging.debug('topology name not supplied')
        topo_name = os.path.basename(topology_dirname(topology_file))
    return topo_name