CI Failure: DiskDistributedNoAckAsyncOverflowRegionDUnitTest > testNoDataSerializer fails with NotSerializableException

org.apache.geode.cache30.DiskDistributedNoAckAsyncOverflowRegionDUnitTest > testNoDataSerializer FAILED

    java.lang.AssertionError: Suspicious strings were written to the log during this run.

    Fix the strings or use IgnoredException.addIgnoredException to ignore.

    -----------------------------------------------------------------------
...
    Found suspect string in 'dunit_suspect-vm2.log' at line 493

    [error 2021/09/04 11:19:51.404 UTC <Asynchronous disk writer for region DiskDistributedNoAckAsyncOverflowRegionDUnitTest_testNoDataSerializer> tid=1025] A DiskAccessException has occurred while writing to the disk for disk store DiskDistributedNoAckAsyncOverflowRegionDUnitTest_testNoDataSerializer. The cache will be closed.
    org.apache.geode.cache.DiskAccessException: For DiskStore: DiskDistributedNoAckAsyncOverflowRegionDUnitTest_testNoDataSerializer: Fatal error from asynchronous flusher thread, caused by org.apache.geode.SerializationException: An IOException was thrown while serializing.
    	at org.apache.geode.internal.cache.DiskStoreImpl$FlusherThread.doAsyncFlush(DiskStoreImpl.java:1796)
    	at org.apache.geode.internal.cache.DiskStoreImpl$FlusherThread.run(DiskStoreImpl.java:1710)
    	at java.lang.Thread.run(Thread.java:748)
    Caused by: org.apache.geode.SerializationException: An IOException was thrown while serializing.
    	at org.apache.geode.internal.cache.EntryEventImpl.serialize(EntryEventImpl.java:2107)
    	at org.apache.geode.internal.cache.EntryEventImpl.serialize(EntryEventImpl.java:2090)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.createValueWrapper(DiskEntry.java:755)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.createValueWrapperFromEntry(DiskEntry.java:791)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.writeToDisk(DiskEntry.java:809)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.writeToDisk(DiskEntry.java:799)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.writeEntryToDisk(DiskEntry.java:1465)
    	at org.apache.geode.internal.cache.entries.DiskEntry$Helper.doAsyncFlush(DiskEntry.java:1417)
    	at org.apache.geode.internal.cache.DiskStoreImpl$FlusherThread.doAsyncFlush(DiskStoreImpl.java:1752)
    	... 2 more
    Caused by: java.io.NotSerializableException: org.apache.geode.cache30.MultiVMRegionTestCase$LongWrapper
    	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
    	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    	at org.apache.geode.internal.InternalDataSerializer.writeSerializableObject(InternalDataSerializer.java:2187)
    	at org.apache.geode.internal.InternalDataSerializer.basicWriteObject(InternalDataSerializer.java:2056)
    	at org.apache.geode.DataSerializer.writeObject(DataSerializer.java:2839)
    	at org.apache.geode.internal.util.BlobHelper.serializeToBlob(BlobHelper.java:54)
    	at org.apache.geode.internal.cache.EntryEventImpl.serialize(EntryEventImpl.java:2105)