I have a Lua iterator function that I don't have control over:

```lua
for x, y, z in otherfunc(stuff) do
   ...
end

```

I want to write a generic Lua wrapper to this function that skips over some of the values it returns, hiding this implementation detail from my users:

```lua
for x, y, z in myfunc(stuff) do
   -- not every x/y/z triplet will appear here
end

```

Though I happen to have three return values here, how can I handle this generically for any number of return values?