How to know the cts test failure reason of Themetest cases?

I am working with Android-Q. i ran cts test of module CtsThemeHostTestCase, it shows the following error.

I/ConsoleReporter: [1/1 x86_64 CtsThemeHostTestCases 192.xxx.x.x] android.theme.cts.ThemeHostTest#testThemes fail: junit.framework.AssertionFailedError: 1216 failures in theme test
    at junit.framework.Assert.fail(Assert.java:57)
    at junit.framework.Assert.assertTrue(Assert.java:22)
    at junit.framework.TestCase.assertTrue(TestCase.java:192)
    at android.theme.cts.ThemeHostTest.testThemes(ThemeHostTest.java:187)
    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 junit.framework.TestCase.runTest(TestCase.java:176)
    at junit.framework.TestCase.runBare(TestCase.java:141)
    at com.android.tradefed.testtype.DeviceTestResult$1.protect(DeviceTestResult.java:90)
    at com.android.tradefed.testtype.DeviceTestResult.runProtected(DeviceTestResult.java:65)
    at com.android.tradefed.testtype.DeviceTestResult.run(DeviceTestResult.java:94)
    at junit.framework.TestCase.run(TestCase.java:129)
    at com.android.tradefed.testtype.DeviceTestCase.run(DeviceTestCase.java:181)
    at com.android.tradefed.testtype.JUnitRunUtil.runTest(JUnitRunUtil.java:53)
    at com.android.tradefed.testtype.JUnitRunUtil.runTest(JUnitRunUtil.java:37)
    at com.android.tradefed.testtype.DeviceTestCase.run(DeviceTestCase.java:146)
    at com.android.tradefed.testtype.HostTest.runRemoteTest(HostTest.java:608)
    at com.android.tradefed.testtype.HostTest.runTestClasses(HostTest.java:535)
    at com.android.tradefed.testtype.HostTest.run(HostTest.java:525)
    at com.android.compatibility.common.tradefed.testtype.JarHostTest.run(JarHostTest.java:53)
    at com.android.tradefed.testtype.suite.GranularRetriableTestWrapper.intraModuleRun(GranularRetriableTestWrapper.java:413)
    at com.android.tradefed.testtype.suite.GranularRetriableTestWrapper.run(GranularRetriableTestWrapper.java:229)
    at com.android.tradefed.testtype.suite.ModuleDefinition.run(ModuleDefinition.java:466)
    at com.android.tradefed.testtype.suite.ITestSuite.runSingleModule(ITestSuite.java:691)
    at com.android.tradefed.testtype.suite.ITestSuite.run(ITestSuite.java:592)
    at com.android.tradefed.invoker.InvocationExecution.runTests(InvocationExecution.java:480)
    at com.android.tradefed.invoker.TestInvocation.prepareAndRun(TestInvocation.java:380)
    at com.android.tradefed.invoker.TestInvocation.performInvocation(TestInvocation.java:230)
    at com.android.tradefed.invoker.TestInvocation.invoke(TestInvocation.java:754)
    at com.android.tradefed.command.CommandScheduler$InvocationThread.run(CommandScheduler.java:591)

What may be the reason for test failure? Is there any changes that i have to do.