Resize a volume to new GB size, must be larger than original.
        :param volumeObj: ScaleIO Volume Object
        :param sizeInGb: New size in GB (have to be larger than original)
        :param bsize: 1000
        :return: POST request response
        :rtype: Requests POST response object

def resize_volume(self, volumeObj, sizeInGb, bsize=1000):
        """
        Resize a volume to new GB size, must be larger than original.
        :param volumeObj: ScaleIO Volume Object
        :param sizeInGb: New size in GB (have to be larger than original)
        :param bsize: 1000
        :return: POST request response
        :rtype: Requests POST response object
        """
        current_vol = self.get_volume_by_id(volumeObj.id)
        if current_vol.size_kb > (sizeInGb * bsize * bsize):
            raise RuntimeError(
                "resize_volume() - New size needs to be bigger than: %d KBs" % current_vol.size_kb)
        
        resizeDict = { 'sizeInGB' : str(sizeInGb) }
        response = self.conn.connection._do_post("{}/{}{}/{}".format(
            self.conn.connection._api_url, "instances/Volume::", volumeObj.id, 'action/setVolumeSize'), json=resizeDict)
        return response