How to use the betterbib.errors.NotFoundError function in betterbib

params = {
            "q": payload,
            "format": "json",
            "h": 2,  # max number of results (hits)
        }

        r = requests.get(self.api_url, params=params)
        if not r.ok:
            raise HttpError("Failed request to {}".format(self.api_url))

        data = r.json()

        try:
            results = data["result"]["hits"]["hit"]
        except KeyError:
            raise NotFoundError("No match")

        if len(results) == 1:
            return _dblp_to_pybtex(results[0]["info"])

        return _dblp_to_pybtex(heuristic_unique_result(results, d)["info"])

# crossref etiquette,
        # 
        headers = {
            "User-Agent": "betterbib/{} ({}; mailto:{})".format(
                __version__, __website__, __author_email__
            )
        }

        r = requests.get(self.api_url, params=params, headers=headers)
        if not r.ok:
            raise HttpError("Failed request to {}".format(self.api_url))

        results = r.json()["message"]["items"]

        if not results:
            raise NotFoundError("No match")

        if len(results) == 1:
            return self._crossref_to_pybtex(results[0])

        return self._crossref_to_pybtex(heuristic_unique_result(results, d))

def find_unique(self, entry):
        d = pybtex_to_dict(entry)

        if "title" not in d and "doi" not in d and "author" not in d:
            raise NotFoundError("Not enough input data")

        L = []

        keys = [
            "title",
            "journal",
            "doi",
            "pages",
            "year",
            "volume",
            "number",
            "publisher",
        ]
        for key in keys:
            try:
                L.append(d[key])