def via_omkey(self, omkey, det_id):
        """Return DOM for given OMkey (DU, floor)"""
        du, floor = omkey
        try:
            return DOM.from_json([
                d for d in self._json if d["DU"] == du and d["Floor"] == floor
                and d["DetOID"] == det_id
            ][0])
        except IndexError:
            log.critical(
                "No DOM found for OMKey '{0}' and DetOID '{1}'.".format(
                    omkey, det_id
                )
            )
Return DOM for given OMkey (DU, floor)