I have a habit of not passing all parameters into function calls if I don't strictly need them. For GObject functions which explicitly accept NULL, that's not a problem. It only becomes an issue when I try to opt out of passing a bit flags parameter, as I expect LGI to default to using 0. In these cases, I currently need to explicitly pass 0 or a flag which resolves to 0 to achieve this. Given Lua's dynamically typed nature, this feels like an opportunity to give the user some leeway.