I’m getting mockito exception when doing the stubbing:

@Mock
RetryTemplate retryTemplate;

@Test
public void testSubmitCreditTransaction() {
    when(retryTemplate.execute(any())).thenAnswer(invocation -> {
        RetryCallback retry = invocation.getArgument(0);
        return retry.doWithRetry(null);
    });

    ...
}

the exception is:

org.mockito.exceptions.misusing.InvalidUseOfMatchersException

what did I get wrong?