Stream output to a file (Rust)

use lumis::{
    languages::Language, themes, write_highlight,
    HtmlInlineBuilder,
};
use std::fs::File;

let formatter = HtmlInlineBuilder::new()
    .language(Language::Rust)
    .theme(Some(themes::get("onedark").unwrap()))
    .build()
    .unwrap();

let mut file = File::create("output.html").unwrap();
write_highlight(&mut file, "fn main() {}", formatter)
    .unwrap();