FILE_NOTIFY_CHANGE_SIZE is not several options separated by underscores. It is one word, and is a constant exported from that module.

If his line doesn't match the correct function call, that will be a problem for later. The compilation isn't getting that far, choking on the use.

But the next paragraph does say “($filter can also be an integer composed from the FILE_NOTIFY_CHANGE_* constants.)” so that's the form he's using.