1{"SetOption":{"value":"filetype=rust"}}
2{"Put":{"state":"// helloˇ\n"}}
3{"Key":"o"}
4{"Get":{"state":"// hello\n// ˇ\n","mode":"Insert"}}
5{"Key":"x"}
6{"Key":"escape"}
7{"Key":"shift-o"}
8{"Get":{"state":"// hello\n// ˇ\n// x\n","mode":"Insert"}}