upsert fails in the multi cluster client

(defn client

      "A client for a single compare-and-set register"

      [cluster bucket]

      (reify client/Client

             (setup! [_ test node]

                     (info node "Creating client")

                     (let [obj (.put (. JsonObject create) "value" 0)

                           doc (. JsonDocument create "jepsen-test-document" obj)

                           clusterset1 (new HashSet #{"n1" "n2" "n3"})

                           clusterset2 (new HashSet #{"n4" "n5" "n6"})

                           clusterspec1 (. ClusterSpec create clusterset1)

                           clusterspec2 (. ClusterSpec create clusterset2)

                           clusterlist (java.util.Arrays/asList (into-array [clusterspec1 clusterspec2]))

                           coord (. Coordinators isolated clusterlist 3000)

                           opts (.failureInterval (.maxFailedOperations (. TrafficMonitoringFailureDetector options) 5) 60)

                           detector (. FailureDetectors trafficMonitoring coord opts)

                           mcc (.authenticate (new MultiClusterClient coord detector) "admin123" "pass123")

                           bucket (.openBucket mcc "default" "")]

                          (Thread/sleep 5000)

                          (info "upserted:" (.upsert bucket doc (timeout) (timeunits)))

                          (info node "Client created")

                          (client cluster bucket)))

java.lang.IllegalStateException: Only AsyncSubject is allowed with deferAndWatch (is Observable)

  at com.couchbase.client.java.util.OnSubscribeDeferAndWatch.call(OnSubscribeDeferAndWatch.java:92) ~[couchbase-java-client-2.4.8-mca-dp1.jar:na]

  at com.couchbase.client.java.util.OnSubscribeDeferAndWatch.call(OnSubscribeDeferAndWatch.java:57) ~[couchbase-java-client-2.4.8-mca-dp1.jar:na]

  at rx.Observable.unsafeSubscribe(Observable.java:10346) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.Observable.subscribe(Observable.java:10442) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.Observable.subscribe(Observable.java:10409) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:444) ~[rxjava-1.2.10.jar:1.2.10]

  at rx.observables.BlockingObservable.single(BlockingObservable.java:341) ~[rxjava-1.2.10.jar:1.2.10]

  at com.couchbase.client.mc.BucketProxy.upsert(BucketProxy.java:103) ~[multi-cluster-java-0.2.0.jar:na]

  at couchbase.core$client$reify__573.setup_BANG_(core.clj:228) ~[na:na]

  at jepsen.core$run_case_BANG_$fn__3373.invoke(core.clj:287) ~[jepsen-0.1.6-SNAPSHOT.jar:na]

  at clojure.lang.AFn.applyToHelper(AFn.java:154) ~[clojure-1.8.0.jar:na]

  at clojure.lang.AFn.applyTo(AFn.java:144) ~[clojure-1.8.0.jar:na]

  at clojure.core$apply.invokeStatic(core.clj:646) ~[clojure-1.8.0.jar:na]

  at clojure.core$apply.invoke(core.clj:641) ~[clojure-1.8.0.jar:na]

  at jepsen.util$fcatch$wrapper__945.doInvoke(util.clj:28) ~[jepsen-0.1.6-SNAPSHOT.jar:na]

  at clojure.lang.RestFn.invoke(RestFn.java:408) ~[clojure-1.8.0.jar:na]

  at jepsen.util$real_pmap$launcher__950$fn__951.invoke(util.clj:48) ~[jepsen-0.1.6-SNAPSHOT.jar:na]

  at clojure.core$binding_conveyor_fn$fn__4676.invoke(core.clj:1938) ~[clojure-1.8.0.jar:na]

  at clojure.lang.AFn.call(AFn.java:18) ~[clojure-1.8.0.jar:na]

  at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_131]

  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_131]

  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_131]

  at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_131]