anchor.diff:  
       return(hosts)
   
  +def get_hostname_by_id(instance_id):
  +    client = boto3.client('ec2', region_name=region)
  +    response = client.describe_instances(InstanceIds=[instance_id])
  +    key = 'PrivateDnsName'
  +    host = response['Reservations'][0]['Instances'][0]['NetworkInterfaces'][0]
  +    if not key in host:
  +        print("The instance attribute {} does not exist".format(key))
  +        exit(1)
  +    else:
  +        return(host[key])
  +
   def main():
       opts, args = parser.parse_args()
   
  
positive.code:         hosts = [random.choice(hosts)]
  
      for host in hosts:
          if opts.puppet_class:
              print(host[host_key])
          else:
              print(host)
  
  parser = OptionParser(description='List nodes in this environment')
  
  
negative.code: 
          qs = urllib.urlencode({'query': query})
          res = urllib2.urlopen('https://puppetdb.<%= @app_domain_internal %>/v2/{0}?{1}'.format(endpoint, qs))
          instance_ids = json.load(res)
  
          hosts = []
  
          for instance in instance_ids:
              hosts.append(get_hostname_by_id(instance[host_key]))
  
      else:
          hosts = ec2_nodes(stackname)
  