I tried to call fbAudienceNetwork.size() in my code but ends up with the following error.
\<Warning\>: ERROR: Runtime error ?:0: attempt to call field 'size' (a nil value) stack traceback: [C]: in function 'size' ?: in function \<?:24\>That’s because the api is called “getSize()” 
Looks like the docs are incorrect there…
Thanks for this.
EDIT: Pushed up a fix for the docs. The change will go live shortly.
Sorry for any inconvenience caused