Queueable Finalizer

EmailHelper.apxc

public class EmailHelper {
    public boolean sendErrorNotification(string jobId)
    {
        Messaging.SingleEmailMessage message = new Messaging.SingleEmailMessage();
        message.toAddresses = new String[] { 'itops@salesforcecodex.com' };
        message.subject = 'Error in Job :' +jobId ;
        message.htmlbody  = 'Hello Admin, </br>There is error in job.</br> Please check</br></br>. Apex Job';
        Messaging.SingleEmailMessage[] messages =   new List<Messaging.SingleEmailMessage> {message};
            Messaging.SendEmailResult[] results = Messaging.sendEmail(messages);
        
        if (results[0].success) {
            return true;
        } else {
           return false;
        }
    }
}

SendEmailFinalizer.apxc

public class SendEmailFinalizer implements Finalizer {
  public void execute(FinalizerContext context){
    Id parentQueueableJobId = context.getAsyncApexJobId();
    switch on context.getAsyncApexJobResult() {
      when SUCCESS {
        System.debug('Job ID: ' + parentQueueableJobId + ' Succeeded');
      }
      when UNHANDLED_EXCEPTION {
        //Send notification to IT Ops Team
        EmailHelper.sendErrorNotification(parentQueueableJobId);
        System.Debug('OH NOES! (Job ID: ' + parentQueueableJobId +'):FAILED! with error: ' +  context.getAsyncApexJobException().getMessage());
      }
    } 
  }
}