Add a default constructor for GpxTrackSegment.

Fixes #22

Author: airbreather

doc/release-notes.md

@@ -1,5 +1,8 @@
 # NetTopologySuite.IO.GPX Release Notes
 
+## [0.2.1](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/milestone/5)
+- Add a default constructor for `GpxTrackSegment` so that its `.WithX` methods are actually meaningful ([#22](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/issues/22)).
+
 ## [0.2.0](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/milestone/2)
 - Give most data objects constructors and `.WithX` methods to make it easier to create instances that only set a few members ([#13](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/issues/13)).
 - Add `GpxFile` as a significantly easier way to read + write our underlying data object representation all in one go ([#12](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/issues/12) / [#14](https://github.com/NetTopologySuite/NetTopologySuite.IO.GPX/issues/14)).

src/NetTopologySuite.IO.GPX/GpxTrackSegment.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Xml;
 using System.Xml.Linq;
 
@@ -14,6 +13,13 @@ namespace NetTopologySuite.IO
     /// </remarks>
     public sealed class GpxTrackSegment
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GpxTrackSegment"/> class.
+        /// </summary>
+        public GpxTrackSegment()
+        {
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="GpxTrackSegment"/> class.
         /// </summary>