docstr: target: test drop not existed db
  method: drop a db repeatedly
  expected: exception
docstr_tok: ["target",":","test","drop","not","existed","db","method",":","drop","a","db","repeatedly","expected",":","exception"]
code: def test_drop_not_existed_db(self):
      """
      target: test drop not existed db
      method: drop a db repeatedly
      expected: exception
      """
      self._connect()
  
      db_name = cf.gen_unique_str(prefix)
      self.database_wrap.create_database(db_name)
  
      # drop a not existed db
      self.database_wrap.drop_database(cf.gen_unique_str(prefix))
  
      # drop db
      self.database_wrap.drop_database(db_name)
      self.database_wrap.drop_database(db_name)
  
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 10 for calling the TestDatabaseOperation obj's underlying member method code with example usage: obj.test_drop_not_existed_db() without return types