code: def get(self, sg_id):
          
          secgroup = self.client.show_security_group(sg_id).get('security_group')
          sg_dict = self._sg_name_dict(sg_id, secgroup['security_group_rules'])
          return SecurityGroup(secgroup, sg_dict)
docs: Fetches the security group.
  
          :returns: SecurityGroup object corresponding to sg_id