docstr: method: describe a non-existing rg
  verify: fail with error msg
docstr_tok: ["method",":","describe","a","non-existing","rg","verify",":","fail","with","error","msg"]
code: def test_describe_rg_non_existing(self):
      """
      method: describe a non-existing rg
      verify: fail with error msg
      """
      self._connect()
      non_existing_rg = "non_existing"
      error = {
          ct.err_code: 999,
          ct.err_msg: "failed to describe resource group, err=resource group doesn't exist",
      }
      self.utility_wrap.describe_resource_group(
          name=non_existing_rg,
          check_task=ct.CheckTasks.err_res,
          check_items=error,
      )
  
imports: import pytest
  from base.client_base import TestcaseBase
  from common import common_func
  from common import common_type
  from common.common_type import CaseLabel, CheckTasks
  from utils.util_pymilvus import *
label_desc: Use image node_id 16 for calling the TestResourceGroupParams obj's underlying member method code with example usage: obj.test_describe_rg_non_existing() without return types