Mockito parece estar jogando umUnfinishedVerificationException quando penso que fiz tudo corretamente. Aqui está o meu caso de teste parcial:

HttpServletRequest req = mock(HttpServletRequest.class);
when(req.getHeader("Authorization")).thenReturn("foo");

HttpServletResponse res = mock(HttpServletResponse.class);

classUnderTest.doMethod(req, res); // Use the mock

verify(res, never());
verify(req).setAttribute(anyString(), anyObject());

E aqui está a classe e o método parciais:

class ClassUnderTest extends AnotherClass {
    @Override
    public String doMethod(ServletRequest req, ServletRequest res) {
        // etc.
        return "someString";
    }
}

Ignorando o fato de que você nunca deve zombar de interfaces que você não possui, por que Mockito está me dando a seguinte mensagem?

org.mockito.exceptions.misusing.UnfinishedVerificationException: 
Missing method call for verify(mock) here:
-> at (redacted)

Example of correct verification:
    verify(mock).doSomething()

Also, this error might show up because you verify either of: final/private/equals()/hashCode() methods.
Those methods *cannot* be stubbed/verified.

at [test method name and class redacted]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
... etc