Constant CONSOLE_HTML_FORMAT 

pub const CONSOLE_HTML_FORMAT: &str = r#"<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
{stylesheet}
body {{
    color: {foreground};
    background-color: {background};
}}
</style>
</head>
<body>
    <pre style="font-family:Menlo,'DejaVu Sans Mono',consolas,'Courier New',monospace"><code style="font-family:inherit">{code}</code></pre>
</body>
</html>
"#;

The HTML document template. Port of _export_format.CONSOLE_HTML_FORMAT, verbatim: a Python format string, so literal braces are doubled. Pass it (or your own, as upstream’s code_format=) to export_html_with.