def _urn_to_dpid(urn):
    m = external_switch_re.search(urn)
    
    if not m:
        raise BadURNError(urn)
    
    return m.group('dpid')
Update the proxy when the status item data changes.
dataset/ETHPy150Open fp7-ofelia/ocf/expedient/src/python/plugins/openflow/plugin/gapi/rspec.py/_urn_to_dpid--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/widgets/status_item.py/StatusItem._update_proxy