Workitem setting Approvals programmatically
One answer
I got it....
IApprovals approvals= workItem.getApprovals();
IApprovalDescriptor descriptor= approvals.createDescriptor(WorkItemApprovals.REVIEW_TYPE.getIdentifier(), "Review");
for (IContributorHandle reviewer: reviewers) {
IApproval approval= approvals.createApproval(descriptor, reviewer);
approvals.add(approval);
}