def does_disk_exist(self, parameters, disk):
    gce_service, credentials = self.open_connection(parameters)
    try:
      http = httplib2.Http()
      auth_http = credentials.authorize(http)
      request = gce_service.disks().get(project=parameters[self.PARAM_PROJECT],
        disk=disk, zone=parameters[self.PARAM_ZONE])
      response = request.execute(http=auth_http)
      AppScaleLogger.verbose(str(response), parameters[self.PARAM_VERBOSE])
      return True
    except errors.HttpError:
      return False
Queries Google Compute Engine to see if the specified persistent disk
dataset/ETHPy150Open AppScale/appscale-tools/lib/agents/gce_agent.py/GCEAgent.does_disk_exist