BATCH CLASS

global class Chatterpostsbatch implements Database.batchable<sObject> {

global String queryOpps;

global Chatterpostsbatch(String query){
  queryOpps=query;
  system.debug(queryOpps);
}

global Database.QueryLocator start(Database.BatchableContext bc)
  {
    system.debug(queryOpps);
      return Database.getQueryLocator(queryOpps);
    }
    
    global void execute(Database.BatchableContext bc, List<SObject> lstOpps)
  {
    set<Id> setOppIds = new set<Id>();
    List<EntitySubscription> followers = new List<EntitySubscription> ();
    
    for(SObject o : lstopps)
    {
      setOppIds.add(o.Id);
    }
    if(!setOppIds.Isempty()){   
      System.debug(setOppIds);
        followers =  [select id from EntitySubscription
            where parentid in: setOppIds];
    }
        if(!followers.Isempty()){                    
        delete followers;
        }                  
  }
  
  global void finish(Database.BatchableContext bc)
  {
    //Mail notification...
    //empty;
  }
}

TEST CLASS

@isTest

private class TestClassChatterPosts {
    
    static testMethod void testChatterPostsScheduled() 
    {
        Test.StartTest();
        Chatterpostsschedule cp = new Chatterpostsschedule();
        datetime currentDateTime = datetime.now();
        String min = String.valueOf(math.mod((currentDateTime.minute() + 1),60));
        String schExp = '0 '+ min +' * * * ? ';
        system.schedule('ChatterPost - ' + system.now().format(), schExp, cp);     
        Test.StopTest();
    }
    
    static testMethod void testChatterPostsBatch() 
    {
        //String queryOpps = 'select Id from Opportunity where IsClosed=true and CloseDate <= LAST_N_DAYS:30 limit 1';
        CustomSettingCreation.SettingData();
        
        Account acc = new Account(Name = 'Test');
        insert acc;
        
        Opportunity opp = new Opportunity();        
        opp.name = 'Test';
        opp.AccountId = acc.id;
        insert opp;
        
        EntitySubscription ens = new EntitySubscription();
        insert ens;
        
        Test.StartTest();
        
        String opps = opp.name;
        Chatterpostsbatch   obj = new  Chatterpostsbatch('Test');
        Database.executeBatch(obj);
        
        Test.StopTest();
    }
}

The second method is failing at the place created the instance of the batch. The bold and underlined part unable to cover. Please someone help me to correct it....