def does_zone_exist(self, parameters):
    try:
      conn = self.open_connection(parameters)
      zone = parameters[self.PARAM_ZONE]
      conn.get_all_zones(zone)
      AppScaleLogger.log('Availability zone {0} does exist'.format(zone))
      return True
    except boto.exception.EC2ResponseError:
      AppScaleLogger.log('Availability zone {0} does not exist'.format(zone))
      return False
Retrieves an evaluation.
dataset/ETHPy150Open AppScale/appscale-tools/lib/agents/ec2_agent.py/EC2Agent.does_zone_exist--crossover with--dataset/ETHPy150Open bigmlcom/python/bigml/evaluationhandler.py/EvaluationHandler.get_evaluation