@Test
public void onHttpServerUpgradeWithoutHandlerAdded() throws Exception {

    handler = new Http2ConnectionHandlerBuilder().frameListener(new Http2FrameAdapter()).server(true).build();
    try {
        handler.onHttpServerUpgrade(new Http2Settings());
        fail();
    } catch (Http2Exception e) {
        assertEquals(Http2Error.INTERNAL_ERROR, e.error());
    }
}