in packages/geofire/src/databaseUtils.ts [24:30]
export function decodeGeoFireObject(geoFireObj: Document): Geopoint {
if (geoFireObj && 'l' in geoFireObj && Array.isArray(geoFireObj.l) && geoFireObj.l.length === 2) {
return geoFireObj.l as Geopoint;
} else {
throw new Error('Unexpected location object encountered: ' + JSON.stringify(geoFireObj));
}
}