RuntimeException: Field is not null, field='previousOwner'

Test: com/oracle/jfr/event/runtime/TestBiasedLockRevocationEvents.java

java.lang.RuntimeException: Field is not null, field='previousOwner', value='{
  osName = "process reaper"
  osThreadId = 30739
  javaName = "process reaper"
  javaThreadId = 22
  group = {
    parent = null
    name = "system"
  }
}
': expected {
  osName = "process reaper"
  osThreadId = 30739
  javaName = "process reaper"
  javaThreadId = 22
  group = {
    parent = null
    name = "system"
  }
}
 to equal null
at jdk.testlibrary.Asserts.fail(Asserts.java:540)
at jdk.testlibrary.Asserts.assertEquals(Asserts.java:209)
at jdk.testlibrary.Asserts.assertNull(Asserts.java:420)
at com.oracle.jfr.common.EventField.lambda$isNull$8(EventField.java:83)
at com.oracle.jfr.common.EventField.doAssert(EventField.java:96)
at com.oracle.jfr.common.EventField.isNull(EventField.java:83)
at com.oracle.jfr.event.runtime.TestBiasedLockRevocationEvents.testExitedThreadRevocation(TestBiasedLockRevocationEvents.java:198)
at com.oracle.jfr.event.runtime.TestBiasedLockRevocationEvents.main(TestBiasedLockRevocationEvents.java:34)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:844)