function test_null_stringimport { test_null_string } from "https://deno.land/x/denops_std@v6.4.0/function/vim/mod.ts"; test_null_string(denops: Denops): Promise<string>Return a String that is null. Only useful for testing. Return a String that is null. Only useful for testing. Parametersdenops: DenopsReturnsPromise<string>