CheckpointBarrierTrackerTest.testTwoLastBarriersOneByOne fails on azure

[ERROR] Tests run: 14, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.893 s <<< FAILURE! - in org.apache.flink.streaming.runtime.io.CheckpointBarrierTrackerTest
[ERROR] testTwoLastBarriersOneByOne(org.apache.flink.streaming.runtime.io.CheckpointBarrierTrackerTest)  Time elapsed: 0.093 s  <<< FAILURE!
java.lang.AssertionError: 

Expected: a value less than or equal to <30L>
     but: <33L> was greater than <30L>
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
	at org.junit.Assert.assertThat(Assert.java:956)
	at org.junit.Assert.assertThat(Assert.java:923)
	at org.apache.flink.streaming.runtime.io.CheckpointBarrierTrackerTest.testTwoLastBarriersOneByOne(CheckpointBarrierTrackerTest.java:616)