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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def static_proxy(request):
 """ Serves TinyMCE plugins inside the inline popups and the uploadify SWF, as these are normally static files, and will break with cross-domain JavaScript errors if ``STATIC_URL`` is an external host. URL for the file is passed in via querystring in the inline popup plugin template, and we then attempt to pull out the relative path to the file, so that we can serve it locally via Django. """

    normalize = lambda u: ("//" + u.split("://")[-1]) if "://" in u else u
    url = normalize(request.GET["u"])
    host = "//" + request.get_host()
    static_url = normalize(settings.STATIC_URL)
    for prefix in (host, static_url, "/"):
        if url.startswith(prefix):
            url = url.replace(prefix, "", 1)
    response = ""
    (content_type, encoding) = mimetypes.guess_type(url)
    if content_type is None:
        content_type = "application/octet-stream"
    path = finders.find(url)
    if path:
        if isinstance(path, (list, tuple)):
            path = path[0]
        if url.endswith(".htm"):
            # Inject <base href="{{ STATIC_URL }}"> into TinyMCE
            # plugins, since the path static files in these won't be
            # on the same domain.
            static_url = settings.STATIC_URL + os.path.split(url)[0] + "/"
            if not urlparse(static_url).scheme:
                static_url = urljoin(host, static_url)
            base_tag = "<base href='%s'>" % static_url
            with open(path, "r") as f:
                response = f.read().replace("<head>", "<head>" + base_tag)
        else:
            try:
                with open(path, "rb") as f:
                    response = f.read()
            except IOError:
                return HttpResponseNotFound()
    return HttpResponse(response, content_type=content_type)