docs: function findFeature(geocoder, latitude, longitude, callback) {
    return new Promise(function(resolve, reject) {
      const query = `SELECT * FROM everything WHERE id IN (
                       SELECT feature_id
                       FROM coordinates
                       WHERE latitude BETWEEN $lat - 1.5 AND $lat + 1.5
                       AND longitude BETWEEN $lon - 1.5 AND $lon + 1.5
                       ORDER BY (
                         ($lat - latitude) * ($lat - latitude) +
                           ($lon - longitude) * ($lon - longitude) * $scale
                       ) ASC
                       LIMIT 1
                     )`
  
      const scale = Math.pow(Math.cos(latitude * Math.PI / 180), 2)
  
      geocoder.db.all(query, {
        $lat:   latitude,
        $lon:   longitude,
        $scale: scale
      }, function(err, rows) {
        if (err) {
          if (typeof(callback) == 'function') {
            callback(err, undefined)
          } else if (typeof(reject) == 'function') {
            reject(err)
          }
        } else {
          const result = formatResult(rows)
          if (typeof(callback) == 'function') {
            callback(undefined, result)
          } else if (typeof(resolve) == 'function') {
            resolve(result)
          }
        }
      })
    })
  }