@Override public void getSegmentsImmediatlyFollowing(SegmentId segmentId, StreamObserver<SuccessorResponse> responseObserver) { log.info("getSegmentsImmediatelyFollowing called for segment {} ", segmentId); authenticateExecuteAndProcessResults(() -> this.authHelper.checkAuthorization(segmentId.getStreamInfo().getScope() + "/" + segmentId.getStreamInfo().getStream(), AuthHandler.Permissions.READ), delegationToken -> controllerService.getSegmentsImmediatelyFollowing(segmentId) .thenApply(ModelHelper::createSuccessorResponse) .thenApply(response -> { response.setDelegationToken(delegationToken); return response.build(); }), responseObserver); }