firestore.BulkWriterTest: sendsBackoffBatchAfterOtherEnqueuedBatches failed #614

org.junit.runners.model.TestTimedOutException: test timed out after 1 seconds
	at sun.misc.Unsafe.park(Native Method)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:537)
	at com.google.common.util.concurrent.FluentFuture$TrustedFuture.get(FluentFuture.java:86)
	at com.google.common.util.concurrent.ForwardingFuture.get(ForwardingFuture.java:62)
	at com.google.cloud.firestore.BulkWriter.close(BulkWriter.java:805)
	at com.google.cloud.firestore.BulkWriterTest.sendsBackoffBatchAfterOtherEnqueuedBatches(BulkWriterTest.java:1329)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:299)
	at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:293)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.lang.Thread.run(Thread.java:748)