Attaching a group policy

The following code attaches the managed policy under the group:

attachGroupPolicy(groupName, policyARN); 
........ 
public void attachGroupPolicy(
         String groupName,
         String policyARN) {
     AttachGroupPolicyRequest attachGroupPolicyRequest =
             new AttachGroupPolicyRequest()
                     .withGroupName(groupName)
                     .withPolicyArn(policyARN);

     AttachGroupPolicyResult attachGroupPolicyResult =
             amazonIdentityManagement.
                     attachGroupPolicy(attachGroupPolicyRequest);
 }