Linkage errors in mockito 2.28.2

LinkageCheckerMain with `-a org.mockito:mockito-core:2.28.2,junit:junit:4.12`. Are they valid errors?

```
Class org.mockito.internal.creation.bytebuddy.inject.MockMethodDispatcher is not found;
referenced by 2 class files
org.mockito.internal.creation.bytebuddy.MockMethodAdvice (mockito-core-2.28.2.jar)
org.mockito.internal.creation.bytebuddy.InlineBytecodeGenerator (mockito-core-2.28.2.jar)
Class org.opentest4j.AssertionFailedError is not found;
referenced by 1 class file
org.mockito.exceptions.verification.opentest4j.ArgumentsAreDifferent (mockito-core-2.28.2.jar)

```

LinkageCheckerMain with `-a org.mockito:mockito-core:2.28.2` shows the following errors. Mostly junit classes.

```
Class org.junit.runner.Runner is not found;
referenced by 3 class files
org.mockito.junit.MockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.ConsoleSpammingMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.VerboseMockitoJUnitRunner (mockito-core-2.28.2.jar)
Class org.junit.runner.manipulation.Filterable is not found;
referenced by 4 class files
org.mockito.junit.MockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.ConsoleSpammingMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.VerboseMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.InternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runner.manipulation.NoTestsRemainException is not found;
referenced by 6 class files
org.mockito.junit.MockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.ConsoleSpammingMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.MockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.VerboseMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.StrictRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.rules.MethodRule is not found;
referenced by 1 class file
org.mockito.junit.MockitoRule (mockito-core-2.28.2.jar)
Class org.junit.rules.TestRule is not found;
referenced by 1 class file
org.mockito.junit.VerificationCollector (mockito-core-2.28.2.jar)
Class org.junit.runner.notification.RunNotifier is not found;
referenced by 5 class files
org.mockito.runners.ConsoleSpammingMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.VerboseMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.internal.junit.UnnecessaryStubbingsReporter (mockito-core-2.28.2.jar)
org.mockito.internal.runners.StrictRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runner.notification.RunListener is not found;
referenced by 4 class files
org.mockito.runners.ConsoleSpammingMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.runners.VerboseMockitoJUnitRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
org.mockito.internal.runners.util.FailureDetector (mockito-core-2.28.2.jar)
Class org.mockito.internal.creation.bytebuddy.inject.MockMethodDispatcher is not found;
referenced by 2 class files
org.mockito.internal.creation.bytebuddy.MockMethodAdvice (mockito-core-2.28.2.jar)
org.mockito.internal.creation.bytebuddy.InlineBytecodeGenerator (mockito-core-2.28.2.jar)
Class org.hamcrest.Matcher is not found;
referenced by 2 class files
org.mockito.internal.hamcrest.HamcrestArgumentMatcher (mockito-core-2.28.2.jar)
org.mockito.internal.hamcrest.MatcherGenericTypeExtractor (mockito-core-2.28.2.jar)
Class org.hamcrest.StringDescription is not found;
referenced by 1 class file
org.mockito.internal.hamcrest.HamcrestArgumentMatcher (mockito-core-2.28.2.jar)
Class org.hamcrest.BaseMatcher is not found;
referenced by 1 class file
org.mockito.internal.hamcrest.MatcherGenericTypeExtractor (mockito-core-2.28.2.jar)
Class org.junit.runners.model.Statement is not found;
referenced by 3 class files
org.mockito.internal.junit.JUnitRule (mockito-core-2.28.2.jar)
org.mockito.internal.junit.VerificationCollectorImpl (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runners.model.FrameworkMethod is not found;
referenced by 1 class file
org.mockito.internal.junit.JUnitRule (mockito-core-2.28.2.jar)
Class org.junit.runner.notification.Failure is not found;
referenced by 2 class files
org.mockito.internal.junit.UnnecessaryStubbingsReporter (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runner.Description is not found;
referenced by 2 class files
org.mockito.internal.junit.UnnecessaryStubbingsReporter (mockito-core-2.28.2.jar)
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runners.model.InitializationError is not found;
referenced by 1 class file
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.runners.BlockJUnit4ClassRunner is not found;
referenced by 1 class file
org.mockito.internal.runners.DefaultInternalRunner (mockito-core-2.28.2.jar)
Class org.junit.Test is not found;
referenced by 1 class file
org.mockito.internal.runners.util.TestMethodsFinder (mockito-core-2.28.2.jar)
Class org.opentest4j.AssertionFailedError is not found;
referenced by 1 class file
org.mockito.exceptions.verification.opentest4j.ArgumentsAreDifferent (mockito-core-2.28.2.jar)
Class junit.framework.ComparisonFailure is not found;
referenced by 1 class file
org.mockito.exceptions.verification.junit.ArgumentsAreDifferent (mockito-core-2.28.2.jar)
```