/// <summary>
        /// Writes out a GeographyLineString value in geojson format.
        /// {
        ///      "__metadata": {"type": "Edm.GeographyLineString"}, 
        ///      { "type" :"LineString",
        ///          "coordinates": { [-122.1202778,47.6741667] } ,
        ///          "crs":{"type":"name","properties":{"name":"EPSG:4326"}}
        ///      }
        /// }
        /// </summary>
        /// <param name="geographyLineStringValue">The geography value to serialize into Json</param>
        /// <param name="writer">The Json writer being used to write out a Json payload</param>
        private static void WriteGeographyLineString(GeographyLineString lineString, JsonWriter writer)
        {
            // { 
            writer.StartObjectScope();

            //  "__metadata":
            writer.WriteName(JsonMetadataString);
            //      {
            writer.StartObjectScope();

            // "type"
            writer.WriteName(JsonTypeString);

            // "Edm.GeographyLineString"
            writer.WriteValue(Gml_Edm_GeographyLineStringName);

            //      }
            writer.EndScope();

            //  "type":"LineString",
            writer.WriteName(JsonTypeString);
            writer.WriteValue(GmlLineString);

            //  "coordinates":
            writer.WriteName(JsonCoOrdinatesString);

            // [
            writer.StartArrayScope();
            foreach (var point in lineString.Points)
            {
                WritePointCoordinates(writer, point);
            }

            // ]
            writer.EndScope();

            // 	"crs": {"type": "name", "properties": {"name": "EPSG:4326"}}
            WriteCrsElement(writer, lineString.CoordinateSystem.EpsgId);

            // }
            writer.EndScope();
        }
 /// <summary>
 /// Writes out a geography point's Co-ordinates in JSON
 /// </summary>
 /// <param name="writer">The Json Writer being used to write out the results.</param>
 /// <param name="point">The Point to serialize into JSON</param>
 private static void WritePointCoordinates(JsonWriter writer, GeographyPoint point)
 {
     writer.StartArrayScope();
     writer.WriteValue(point.Longitude);
     writer.WriteValue(point.Latitude);
     writer.EndScope();
 }