class_docstr: Test case of database 
class_docstr_tok: ["Test","case","of","database"]
docstr: get invalid string
  :param request:
  :type request:
docstr_tok: ["get","invalid","string",":","param","request",":",":","type","request",":"]
code: def get_invalid_string(self, request):
      """
      get invalid string
      :param request:
      :type request:
      """
      yield request.param
  
imports: import pandas
  import pytest
  from base.client_base import TestcaseBase
  from common.common_type import CheckTasks, CaseLabel
  from common import common_func
  from common import common_type
  from utils.util_log import test_log
label_desc: Use image node_id 2 for calling the TestDatabaseParams obj's underlying member method code with example usage: obj.get_invalid_string(request) without return types