@Test
public void readUnknownFrame() throws Http2Exception {

    ByteBuf input = Unpooled.buffer();
    ByteBuf payload = Unpooled.buffer();
    try {
        payload.writeByte(1);
        writeFrameHeader(input, payload.readableBytes(), (byte) 0xff, new Http2Flags(), 0);
        input.writeBytes(payload);
        frameReader.readFrame(ctx, input, listener);
        verify(listener).onUnknownFrame(
                ctx, (byte) 0xff, 0, new Http2Flags(), payload.slice(0, 1));
    } finally {
        payload.release();
        input.release();
    }
}