Get list of SDC mapped to a specific volume
        :param volObj: ScaleIO volume object
        :return: List of ScaleIO SDC objects (empty list if no mapping exist)
        :rtype: SDC object

def get_sdc_for_volume(self, volObj):
        """
        Get list of SDC mapped to a specific volume
        :param volObj: ScaleIO volume object
        :return: List of ScaleIO SDC objects (empty list if no mapping exist)
        :rtype: SDC object
        """
        sdcList = []
        if volObj.mapped_sdcs is not None:
            for sdc in volObj.mapped_sdcs:
                sdcList.append(sdc)
        if len(sdcList) == 0:
            self.conn.logger.debug("No SDCs mapped to volume: %s-(%s)" % (volObj.name, volObj.id))
            return []
        # returning an empty list is
        # valid for snapshots or volumes.
        return sdcList