Merge branch 'shevchenko_3.x' into '3.x'

Small changes

See merge request !1

src/LibVLCSharp.Tests/MediaPlayerTests.cs

@@ -60,7 +60,7 @@ namespace LibVLCSharp.Tests
             mp.Playing += (sender, args) =>
             {
                 var chapters = mp.FullChapterDescriptions(-1);
-                Assert.IsNotNull(chapters);
+                Assert.IsNotEmpty(chapters);
                 Assert.AreEqual(chapters.Length, mp.ChapterCount);
                 tcs.SetResult(true);
             };

src/LibVLCSharp/Shared/MediaPlayer.cs

@@ -1449,8 +1449,8 @@ namespace LibVLCSharp.Shared
         /// </summary>
         /// <param name="titleIndex">Index of the title to query for chapters (uses current title if set to -1)</param>
         /// <returns>Array of chapter descriptions.</returns>
-        public ChapterDescription[] FullChapterDescriptions(int titleIndex) => MarshalUtils.Retrieve(NativeReference, 
-            (IntPtr nativeRef, out IntPtr array) => 
+        public ChapterDescription[] FullChapterDescriptions(int titleIndex = -1) => MarshalUtils.Retrieve(NativeReference,
+            (IntPtr nativeRef, out IntPtr array) =>
             {
                 var count = Native.LibVLCMediaPlayerGetFullChapterDescriptions(nativeRef, titleIndex, out array);
                 // the number of chapters (-1 on error)