Adding multiple approvers to an approval item

Hi All,
          How to add multiple approvers to an approval item programatically? createApproval method allows only 1 contributor handle. How to add multiple approvers?

My code is :

IContributorService IConService = getService(IContributorService.class);
             IContributorHandle user = IConService.fetchContributorByUserId("ccm_user");
            IApprovals approvals= sourceworkItem.getApprovals();
            IApprovalDescriptor descriptor= approvals.createDescriptor(WorkItemApprovals.APPROVAL_TYPE.getIdentifier(), "Lead Developer Approval");

                
                     IApproval approval= approvals.createApproval(descriptor, user);
                                             approvals.add(approval);

Thanks.