java.lang.NullPointerException

2019-08-08 16:08:42.781 13195-13195/com.p3group.bmw E/MyTasksTodayPresenter: loadTasksFail
    java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
        at java.lang.StringBuilder.(StringBuilder.java:113)
        at com.p3group.bmw.data.models.CustomerLight.applyInterestedInVehicle(CustomerLight.java:73)
        at com.p3group.bmw.data.models.CustomerLight.updateCustomer(CustomerLight.java:57)
        at com.p3group.bmw.data.models.Task.updateCustomer(Task.java:96)
        at com.p3group.bmw.page.mytasks.today.MyTasksTodayPresenter.lambda$loadTasks$1$MyTasksTodayPresenter(MyTasksTodayPresenter.java:80)
        at com.p3group.bmw.page.mytasks.today.MyTasksTodayPresenter$$Lambda$1.apply(Unknown Source:4)
        at io.reactivex.internal.operators.flowable.FlowableMap$MapSubscriber.onNext(FlowableMap.java:64)
        at io.reactivex.internal.operators.flowable.FlowableFlattenIterable$FlattenIterableSubscriber.drain(FlowableFlattenIterable.java:313)
        at io.reactivex.internal.operators.flowable.FlowableFlattenIterable$FlattenIterableSubscriber.onNext(FlowableFlattenIterable.java:175)
        at io.reactivex.internal.operators.flowable.FlowableSubscribeOn$SubscribeOnSubscriber.onNext(FlowableSubscribeOn.java:97)
        at io.reactivex.internal.operators.flowable.FlowableFlatMap$MergeSubscriber.tryEmitScalar(FlowableFlatMap.java:234)
        at io.reactivex.internal.operators.flowable.FlowableFlatMap$MergeSubscriber.onNext(FlowableFlatMap.java:152)
        at io.reactivex.internal.operators.flowable.FlowableOnBackpressureLatest$BackpressureLatestSubscriber.drain(FlowableOnBackpressureLatest.java:129)
        at io.reactivex.internal.operators.flowable.FlowableOnBackpressureLatest$BackpressureLatestSubscriber.onNext(FlowableOnBackpressureLatest.java:68)
        at io.reactivex.internal.operators.flowable.FlowableFromObservable$SubscriberObserver.onNext(FlowableFromObservable.java:52)
        at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeOnObserver.onNext(ObservableSubscribeOn.java:58)
        at com.jakewharton.retrofit2.adapter.rxjava2.CallObservable.subscribeActual(CallObservable.java:43)
        at io.reactivex.Observable.subscribe(Observable.java:11040)
        at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96)
        at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:463)
        at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
        at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:784)