PartiallyFinishedSourcesITCase fails due to assertion error in DrainingValidator.validateOperatorLifecycle

Sep 03 23:17:11 [ERROR] Tests run: 6, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 19.233 s <<< FAILURE! - in org.apache.flink.runtime.operators.lifecycle.PartiallyFinishedSourcesITCase
Sep 03 23:17:11 [ERROR] test[simple graph SINGLE_SUBTASK, failover: true]  Time elapsed: 2.27 s  <<< FAILURE!
Sep 03 23:17:11 java.lang.AssertionError
Sep 03 23:17:11 	at org.junit.Assert.fail(Assert.java:87)
Sep 03 23:17:11 	at org.junit.Assert.assertTrue(Assert.java:42)
Sep 03 23:17:11 	at org.junit.Assert.assertFalse(Assert.java:65)
Sep 03 23:17:11 	at org.junit.Assert.assertFalse(Assert.java:75)
Sep 03 23:17:11 	at org.apache.flink.runtime.operators.lifecycle.validation.DrainingValidator.validateOperatorLifecycle(DrainingValidator.java:56)
Sep 03 23:17:11 	at org.apache.flink.runtime.operators.lifecycle.validation.TestOperatorLifecycleValidator.lambda$checkOperatorsLifecycle$1(TestOperatorLifecycleValidator.java:52)
Sep 03 23:17:11 	at java.util.HashMap.forEach(HashMap.java:1289)
Sep 03 23:17:11 	at org.apache.flink.runtime.operators.lifecycle.validation.TestOperatorLifecycleValidator.checkOperatorsLifecycle(TestOperatorLifecycleValidator.java:47)
Sep 03 23:17:11 	at org.apache.flink.runtime.operators.lifecycle.PartiallyFinishedSourcesITCase.test(PartiallyFinishedSourcesITCase.java:94)