Cannot throw exception

I have a method that throws a custom exception

class SiteRuleService {
    fun extractDomain(uri: URI): String {
        throw InvalidUrlException("Invalid URL or domain <${uri.toASCIIString()}>")
    }
}

class InvalidUrlException(override val message: String = "") : Exception(message)

And a test to exercise this method:

@Test
fun testFindPagechat_InvalidUrlForBadUrl() {
    val inputUri = URI("http://example.com")
    doThrow(InvalidUrlException("Invalid URL or domain"))
            .whenever(siteRuleService).extractDomain(inputUri)

    try {
        siteRuleService.extractDomain(inputUri)
        fail("Expected exception")
    } catch (e: InvalidUrlException) {
        assertEquals("Invalid URL or domain", e.message)
    }
}

But Mockito complains because the method doesnt’ declare IUE as a checked exception (since we can’t in Kotlin):

org.mockito.exceptions.base.MockitoException: 
Checked exception is invalid for this method!
Invalid: net.forumforall.kuorum.pagechat.InvalidUrlException: Invalid URL or domain

Any way around this?

[jibidus]

Here is a workaround :

doAnswer { throw InvalidUrlException("Invalid URL or domain") }
            .whenever(siteRuleService)
            .extractDomain(inputUri)

[james-ralston]

Is it a good idea to add annotations to source code just for testing purposes? I understand writing testable code and writing in a way that makes it testable, but this seems like a stretch and introduces something excluded from the language