JustIdentity

Here, I am using keymap `` to toggle vim extension on/off. But, after turning off then pasting something using ``, this happened:  [Code Sandbox](https://codesandbox.io/s/pasting-after-toggling-ss3u9i)

Description --- As the titled written, I can't change EditorState using [`Vim.defineEx`](https://codemirror.net/5/doc/manual.html#vimapi_extending). Usually I want to preserve extension between different EditorState, so I am using [`StateEffect`](https://codemirror.net/docs/ref/#state.StateEffect). I thought that was...