Function writable_file 

fn writable_file<'a>(
    packs: &'a mut BTreeMap<String, Pack>,
    dependencies: &'a mut Dependencies,
    file: &FileRef,
) -> Result<&'a mut RFile>

Returns a file of an open pack, the game files or the parent packs, mutably.

Errors

Fails if the file doesn’t exist, or if it’s an Assembly Kit table, which isn’t stored as a file.