fix: add Dictionary TryAdd extension for Unity 2021

Runtime/Client/DotNetStandardClient.cs

@@ -4,6 +4,10 @@
 using System.Net.Http;
 using System.Threading.Tasks;
 
+#if !UNITY_2022_1_OR_NEWER
+using BugSplatUnity.Runtime.Util.Extensions;
+#endif
+
 namespace BugSplatUnity.Runtime.Client
 {
     internal interface IDotNetStandardExceptionClient

Runtime/Reporter/WebGLReporter.cs

@@ -3,8 +3,12 @@
 using BugSplatUnity.Runtime.Util;
 using System;
 using System.Collections;
-using UnityEngine;
-
+using UnityEngine;
+
+#if !UNITY_2022_1_OR_NEWER
+using BugSplatUnity.Runtime.Util.Extensions;
+#endif
+
 namespace BugSplatUnity.Runtime.Reporter
 {
     internal class WebGLReporter : IExceptionReporter

Runtime/Util/DictionaryExtensions.cs

@@ -0,0 +1,17 @@
+#if !UNITY_2022_1_OR_NEWER
+using System.Collections.Generic;
+
+namespace BugSplatUnity.Runtime.Util.Extensions
+{
+    public static class DictionaryExtensions
+    {
+        public static bool TryAdd<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key, TValue value)
+        {
+            if (dictionary == null) return false;
+            if (dictionary.ContainsKey(key)) return false;
+            dictionary.Add(key, value);
+            return true;
+        }
+    }
+}
+#endif

Runtime/Util/ReportPostOptionsExtensions.cs

@@ -1,6 +1,10 @@
 using BugSplatUnity.Runtime.Settings;
 using System.Collections.Generic;
 
+#if !UNITY_2022_1_OR_NEWER
+using BugSplatUnity.Runtime.Util.Extensions;
+#endif
+
 namespace BugSplatUnity.Runtime.Util
 {
     internal static class ReportPostOptionsExtensions

Tests/Runtime/Client/Fakes/FakeUnityWebClient.cs

@@ -64,6 +64,8 @@ class FakeExceptionPostOptions : IReportPostOptions
         public string Key { get; set; }
         public string Notes { get; set; }
         public string User { get; set; }
-        public int CrashTypeId { get; set; }
+        public int CrashTypeId { get; set; }
+
+        public Dictionary<string, string> AdditionalAttributes => new Dictionary<string,string>();
     }
 }