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