@isTest
public class campaignClassTest {
    @isTest static void testCampaignMethod() {
        // Create test data
        List<Lead>llist=new List<Lead>();
        Lead ld=new Lead();
        ld.LastName='kp';
        ld.MultiPic__c='P1';
        ld.Company='hTTp';
        ld.Status='Closed-Converted';
        llist.add(ld);
        insert llist;
        
        String s=ld.Id;
              
        Campaign camp=new Campaign();
        camp.Name='Monthly-Newsletter';
        insert camp;
        
        CampaignMember cm=new CampaignMember();
        cm.CampaignId=camp.Id;
        cm.LeadId=s;
        insert cm;
        
        Test.startTest();
       campaignClass.campaignMethod(llist);
        Test.stopTest();
        
    }    
}