import { funcref } from "https://deno.land/x/denops_std@v6.4.0/function/mod.ts";
Just like function(), but the returned Funcref will lookup
the function by reference, not by name. This matters when the
function {name} is redefined later.
Unlike function(), {name} must be an existing user function.
It only works for an autoloaded function if it has already
been loaded (to avoid mistakenly loading the autoload script
when only intending to use the function name, use function()
instead). {name} cannot be a builtin function.
Returns 0 on error.
Can also be used as a method:
GetFuncname()->funcref([arg])