def no2index_around_coords(self, lat, lon, start=None, interval=None):
        """
        Queries the OWM Weather API for Nitrogen Dioxide values sampled in the
        surroundings of the provided geocoordinates and in the specified time
        interval.
        A *NO2Index* object instance is returned, encapsulating a
        *Location* object and the list of NO2 samples
        If `start` is not provided, the latest available NO2 samples are
        retrieved
        If `start` is provided but `interval` is not, then `interval` defaults
        to the maximum extent, which is: `year`

        :param lat: the location's latitude, must be between -90.0 and 90.0
        :type lat: int/float
        :param lon: the location's longitude, must be between -180.0 and 180.0
        :type lon: int/float
        :param start: the object conveying the start value of the search time
            window start (defaults to ``None``). If not provided, the latest
            available NO2 samples value are retrieved
        :type start: int, ``datetime.datetime`` or ISO8601-formatted
            string
        :param interval: the length of the search time window starting at
           `start` (defaults to ``None``). If not provided, 'year' is used
        :type interval: str among: 'minute', 'hour', 'day', 'month, 'year'
        :return: a *NO2Index* instance or ``None`` if data is not available
        :raises: *ParseResponseException* when OWM Weather API responses' data
            cannot be parsed, *APICallException* when OWM Weather API can not be
            reached, *ValueError* for wrong input values
        """
        geo.assert_is_lon(lon)
        geo.assert_is_lat(lat)
        params = {'lon': lon, 'lat': lat, 'start': start, 'interval': interval}
        json_data = self._pollapi.get_no2(params)
        no2index = self._parsers['no2index'].parse_JSON(json_data)
        if interval is None:
            interval = 'year'
        no2index._interval = interval
        return no2index
Queries the OWM Weather API for Nitrogen Dioxide values sampled in the
        surroundings of the provided geocoordinates and in the specified time
        interval.
        A *NO2Index* object instance is returned, encapsulating a
        *Location* object and the list of NO2 samples
        If `start` is not provided, the latest available NO2 samples are
        retrieved
        If `start` is provided but `interval` is not, then `interval` defaults
        to the maximum extent, which is: `year`

        :param lat: the location's latitude, must be between -90.0 and 90.0
        :type lat: int/float
        :param lon: the location's longitude, must be between -180.0 and 180.0
        :type lon: int/float
        :param start: the object conveying the start value of the search time
            window start (defaults to ``None``). If not provided, the latest
            available NO2 samples value are retrieved
        :type start: int, ``datetime.datetime`` or ISO8601-formatted
            string
        :param interval: the length of the search time window starting at
           `start` (defaults to ``None``). If not provided, 'year' is used
        :type interval: str among: 'minute', 'hour', 'day', 'month, 'year'
        :return: a *NO2Index* instance or ``None`` if data is not available
        :raises: *ParseResponseException* when OWM Weather API responses' data
            cannot be parsed, *APICallException* when OWM Weather API can not be
            reached, *ValueError* for wrong input values