what is the solution for this error(Method does not exist or incorrect signature: void StartTest() from the type test) in Salesforce?

i am experiencing this error (Method does not exist or incorrect signature: void StartTest() from the type test) in the asynchronous trail's future method unit..

here's my code

@isTest
public class AccountProcessorTest {
public static testmethod void AccountProcessorTest1(){
Account testaccount = new Account();
testaccount.name = 'Test Account';
insert testaccount;

Contact testcontact = new Contact();
testcontact.FirstName = 'Chief';
testcontact.LastName = 'Hopper';
testcontact.AccountId = testaccount.Id;
insert testcontact;

set<Id> AccId = new set<Id>();
AccId.add(testaccount.Id);

Test.StartTest();
AccountProcessor.countContacts(AccId);
Test.StopTest();
Account ACC = [select Number_of_Contacts__c from Account where id = :testaccount.Id LIMIT 1];
System.assertEquals ( Integer.valueOf(ACC.Number_of_Contacts__c) ,1);
}

}

Can anyone help me on how to tackle this error

• This discussion was modified 6 years ago by  Shubham.