chromium/third_party/blink/web_tests/external/wpt/html/semantics/embedded-content/the-img-element/404-response-with-actual-image-data.py

from base64 import decodebytes

def main(req, res):
    return 404, [(b'Content-Type', b'image/png')], decodebytes(b"iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAAhSURBVDhPY3wro/KfgQLABKXJBqMGjBoAAqMGDLwBDAwAEsoCTFWunmQAAAAASUVORK5CYII=")