Function node_options 

pub(crate) fn node_options(command: &str, rest: &[&str]) -> NodeOptions

Parses the options both node-starting commands take.

Everything after -- belongs to the daemon and is not looked at, so a daemon flag this side has never heard of still reaches it. Without that, every new daemon flag would be a reason to stop using these commands and go back to spelling out the whole invocation.