def __describe_instances(self, parameters):
    conn = self.open_connection(parameters)
    reservations = conn.get_all_instances()
    instances = [i for r in reservations for i in r.instances]
    return instances
Query the back-end EC2 services for instance details and return
dataset/ETHPy150Open AppScale/appscale-tools/lib/agents/ec2_agent.py/EC2Agent.__describe_instances