It seems MockWebServer uses an internal class in OkHttp that triggers when we upgrade our KTor stack (with OkHttp):
java.lang.NoClassDefFoundError: okhttp3/internal/Util
at okhttp3.mockwebserver.MockWebServer.<init>(MockWebServer.kt:103)
at no.nav.security.mock.oauth2.http.MockWebServerWrapper.<init>(OAuth2HttpServer.kt:80)
at no.nav.security.mock.oauth2.http.MockWebServerWrapper.<init>(OAuth2HttpServer.kt:77)
at no.nav.security.mock.oauth2.OAuth2Config.<init>(OAuth2Config.kt:36)
at no.nav.security.mock.oauth2.MockOAuth2Server.<init>(MockOAuth2Server.kt:48)
....truncated...