def transfer_if_enough_space(self, size, src, dst):
        LOG.info('Calculate free space on the destination cloud.')
        dst_free_space = self.free_space(self.clouds[DST], dst)
        if dst_free_space > size:
            LOG.info("Enough space found on %s", dst)
            LOG.info('Start copying volume.')

            return self.run_transfer(src, dst)
        LOG.warning("No enough space on %s", dst)
Returns the  pids of the program to kill all the process tree
dataset/ETHPy150Open MirantisWorkloadMobility/CloudFerry/cloudferry/lib/os/actions/cinder_database_manipulation.py/CopyVolumes.transfer_if_enough_space--crossover with--dataset/ETHPy150Open jgilhutton/pyxiewps_WPShack-Python/pyxiewps-EN.py/Engine.get_process_children