import { assert_notequal } from "https://deno.land/x/denops_std@v6.3.0/function/vim/mod.ts";
The opposite of assert_equal(): add an error message to
v:errors when {expected} and {actual} are equal.
Also see assert-return.
Can also be used as a method:
mylist->assert_notequal([1, 2, 3])