NullPointerException in StoreAppender

[nicktindall]

Failed test https://teamcity.chronicle.software/buildConfiguration/Chronicle_ChronicleQueueEnterprise_SnapshotJava11/941796?expandBuildDeploymentsSection=false&hideTestsFromDependencies=false&expandBuildTestsSection=true&hideProblemsFromDependencies=false&expandBuildProblemsSection=true&expandBuildChangesSection=true

This has failed in the same way numerous times. The wire field is marked as @Nullable but no null check is performed.

target/testAppendedSkipToEndMultiThreaded_7__DELTA_BINARY_wbm_None_rbm_None_named_false_encrypted_null_-1111-gufget2o2p
      Exception in thread "Thread-40" java.lang.NullPointerException
        at net.openhft.chronicle.queue.impl.single.StoreAppender$StoreAppenderContext.index(StoreAppender.java:1147)
        at net.openhft.chronicle.queue.impl.single.DeltaWireAppender.writingDocument(DeltaWireAppender.java:33)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.writingDocument(StoreAppender.java:417)
        at net.openhft.chronicle.queue.impl.single.DeltaWireAppender.writingDocument(DeltaWireAppender.java:14)
        at net.openhft.chronicle.queue.impl.single.SingleChronicleQueueTest.writeTestDocument(SingleChronicleQueueTest.java:2596)
        at net.openhft.chronicle.queue.impl.single.SingleChronicleQueueTest.lambda$testAppendedSkipToEndMultiThreaded$90(SingleChronicleQueueTest.java:2376)
        at java.base/java.lang.Thread.run(Thread.java:829)
      Exception in thread "Thread-37" net.openhft.chronicle.core.io.ClosedIllegalStateException: Closed
        at net.openhft.chronicle.core.io.ManagedCloseable.throwExceptionIfClosed(ManagedCloseable.java:68)
        at net.openhft.chronicle.queue.impl.WireStorePool.acquire(WireStorePool.java:50)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.setCycle2(StoreAppender.java:331)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.setWireIfNull(StoreAppender.java:536)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.prepareAndReturnWriteContext(StoreAppender.java:450)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.writingDocument(StoreAppender.java:429)
        at net.openhft.chronicle.queue.impl.single.DeltaWireAppender.writingDocument(DeltaWireAppender.java:32)
        at net.openhft.chronicle.queue.impl.single.StoreAppender.writingDocument(StoreAppender.java:417)
        at net.openhft.chronicle.queue.impl.single.DeltaWireAppender.writingDocument(DeltaWireAppender.java:14)
        at net.openhft.chronicle.queue.impl.single.SingleChronicleQueueTest.writeTestDocument(SingleChronicleQueueTest.java:2596)
        at net.openhft.chronicle.queue.impl.single.SingleChronicleQueueTest.lambda$testAppendedSkipToEndMultiThreaded$90(SingleChronicleQueueTest.java:2376)
        at java.base/java.lang.Thread.run(Thread.java:829)