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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 WSGIHandler(self):
 """Returns GRR's WSGI handler."""

    sdm = werkzeug_wsgi.SharedDataMiddleware(self, {
        "/": config.CONFIG["AdminUI.document_root"],
    })
    # Use DispatcherMiddleware to make sure that SharedDataMiddleware is not
    # used at all if the URL path doesn't start with "/static". This is a
    # workaround for cases when unicode URLs are used on systems with
    # non-unicode filesystems (as detected by Werkzeug). In this case
    # SharedDataMiddleware may fail early while trying to convert the
    # URL into the file path and not dispatch the call further to our own
    # WSGI handler.
    return werkzeug_wsgi.DispatcherMiddleware(self, {
        "/static": sdm,
    })