Flaky test KafkaAdminClientTest.testUnreachableBootstrapServer

org.junit.runners.model.TestTimedOutException: test timed out after 120000 milliseconds
	at java.lang.Object.wait(Native Method)
	at java.lang.Object.wait(Object.java:502)
	at org.apache.kafka.common.internals.KafkaFutureImpl$SingleWaiter.await(KafkaFutureImpl.java:92)
	at org.apache.kafka.common.internals.KafkaFutureImpl.get(KafkaFutureImpl.java:260)
	at org.apache.kafka.clients.admin.KafkaAdminClientTest.testUnreachableBootstrapServer(KafkaAdminClientTest.java:303)

[2019-05-17 06:38:01,854] ERROR Uncaught exception in thread 'kafka-admin-client-thread | adminclient-35': (org.apache.kafka.common.utils.KafkaThread:51)
java.lang.IllegalStateException: Cannot send ClientRequest(expectResponse=true, callback=null, destination=-1, correlationId=0, clientId=mockClientId, createdTimeMs=1558075081853, requestBuilder=MetadataRequestData(topics=[], allowAutoTopicCreation=true, includeClusterAuthorizedOperations=false, includeTopicAuthorizedOperations=false)) since the destination is not ready
	at org.apache.kafka.clients.MockClient.send(MockClient.java:186)
	at org.apache.kafka.clients.admin.KafkaAdminClient$AdminClientRunnable.sendEligibleCalls(KafkaAdminClient.java:943)
	at org.apache.kafka.clients.admin.KafkaAdminClient$AdminClientRunnable.run(KafkaAdminClient.java:1140)
	at java.lang.Thread.run(Thread.java:748)