fs:open(path) -> AsyncTask<File>
fs:create(path) -> AsyncTask<File>
fs:remove(path) -> AsyncTask
fs:remove_all(path) -> AsyncTask
fs:list(path) -> AsyncTask<[]Stat>
fs:stat(path) -> AsyncTask<Stat>
fs:mkdir_all(path) -> AsyncTask
fs:exist(path) -> AsyncTask<bool>
fs:read_all(path) -> AsyncTask<string>
fs:write(path) -> AsyncTask