private void TestRoundTrip(string expected, GeoJsonNamedCoordinateReferenceSystem crs)
        {
            var json = crs.ToJson();
            Assert.Equal(expected, json);

            var rehydrated = BsonSerializer.Deserialize<GeoJsonNamedCoordinateReferenceSystem>(json);
            Assert.Equal(expected, rehydrated.ToJson());
        }
        public void TestExampleFromSpec()
        {
            var crs = new GeoJsonNamedCoordinateReferenceSystem("urn:ogc:def:crs:OGC:1.3:CRS84");
            var expected = "{ 'type' : 'name', 'properties' : { 'name' : 'urn:ogc:def:crs:OGC:1.3:CRS84' } }".Replace("'", "\"");

            TestRoundTrip(expected, (GeoJsonCoordinateReferenceSystem)crs);
            TestRoundTrip(expected, (GeoJsonNamedCoordinateReferenceSystem)crs);
        }