Converts ClientSummary to ExportedNetworkInterfaces.

def Convert(self, metadata, client_summary, token=None):
    """Converts ClientSummary to ExportedNetworkInterfaces."""
    for interface in client_summary.interfaces:
      yield super(ClientSummaryToExportedNetworkInterfaceConverter,
                  self).Convert(
                      metadata, interface, token=token).next()