docs: def do_stack(self,args):
          """Go to the specified stack. stack -h for detailed help"""
          parser = CommandArgumentParser("stack")
          parser.add_argument(dest='stack',help='stack index or name');
          parser.add_argument('-a','--asg',dest='asg',help='descend into specified asg');
          args = vars(parser.parse_args(args))
  
          try:
              index = int(args['stack'])
              if self.stackList == None:
                  self.do_stacks('-s')
              stack = AwsConnectionFactory.instance.getCfResource().Stack(self.stackList[index]['StackName'])
          except ValueError:
              stack = AwsConnectionFactory.instance.getCfResource().Stack(args['stack'])
  
  
          if 'asg' in args:
              AwsProcessor.processorFactory.Stack(stack,stack.name,self).onecmd('asg {}'.format(args['asg']))
          AwsProcessor.processorFactory.Stack(stack,stack.name,self).cmdloop()