TestYARNRunner.testHistoryServerToken failed on trunk

Error Message

null expected:<> but was:<null>

Stacktrace

junit.framework.ComparisonFailure: null expected:<> but was:<null>
	at junit.framework.Assert.assertEquals(Assert.java:81)
	at junit.framework.Assert.assertEquals(Assert.java:87)
	at org.apache.hadoop.mapred.TestYARNRunner$4.answer(TestYARNRunner.java:267)
	at org.apache.hadoop.mapred.TestYARNRunner$4.answer(TestYARNRunner.java:262)
	at org.mockito.internal.stubbing.StubbedInvocationMatcher.answer(StubbedInvocationMatcher.java:31)
	at org.mockito.internal.MockHandler.handle(MockHandler.java:97)
	at org.mockito.internal.creation.MethodInterceptorFilter.intercept(MethodInterceptorFilter.java:47)
	at org.apache.hadoop.mapreduce.v2.api.MRClientProtocol$$EnhancerByMockitoWithCGLIB$$128d95ae.getDelegationToken(<generated>)
	at org.apache.hadoop.mapred.YARNRunner.getDelegationTokenFromHS(YARNRunner.java:194)
	at org.apache.hadoop.mapred.TestYARNRunner$5.run(TestYARNRunner.java:288)
	at org.apache.hadoop.mapred.TestYARNRunner$5.run(TestYARNRunner.java:284)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:396)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1452)
	at org.apache.hadoop.mapred.TestYARNRunner.testHistoryServerToken(TestYARNRunner.java:283)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at junit.framework.TestCase.runTest(TestCase.java:168)
	at junit.framework.TestCase.runBare(TestCase.java:134)
	at junit.framework.TestResult$1.protect(TestResult.java:110)
	at junit.framework.TestResult.runProtected(TestResult.java:128)
	at junit.framework.TestResult.run(TestResult.java:113)
	at junit.framework.TestCase.run(TestCase.java:124)
	at junit.framework.TestSuite.runTest(TestSuite.java:243)
	at junit.framework.TestSuite.run(TestSuite.java:238)
	at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
	at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)