Fix some SonarCloud issues (#1058)

* Fix some SonarCloud issues

* added some xml comments

src/WireMock.Net/Settings/ProxySaveMappingSetting.cs

@@ -1,20 +1,48 @@
+using System;
+using Stef.Validation;
 using WireMock.Matchers;
 
 namespace WireMock.Settings;
 
-public class ProxySaveMappingSetting<T>
+/// <summary>
+/// Represents settings for saving a proxy mapping with a non-nullable value and a specific match behaviour.
+/// </summary>
+/// <typeparam name="T">The non-nullable type of the value associated with the proxy save mapping setting.</typeparam>
+public class ProxySaveMappingSetting<T> where T : notnull
 {
-    public MatchBehaviour MatchBehaviour { get; } = MatchBehaviour.AcceptOnMatch;
+    /// <summary>
+    /// Gets the match behaviour for the proxy save mapping setting.
+    /// </summary>
+    /// <value>The match behaviour which determines how matches are evaluated.</value>
+    public MatchBehaviour MatchBehaviour { get; }
 
+    /// <summary>
+    /// Gets the non-nullable value associated with the proxy save mapping setting.
+    /// </summary>
+    /// <value>The value of type <typeparamref name="T"/>.</value>
     public T Value { get; }
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ProxySaveMappingSetting{T}"/> class with specified non-nullable value and match behaviour.
+    /// </summary>
+    /// <param name="value">The non-nullable value of type <typeparamref name="T"/>.</param>
+    /// <param name="matchBehaviour">The match behaviour (optional, default is <c>MatchBehaviour.AcceptOnMatch</c>.</param>
+    /// <exception cref="ArgumentNullException">Thrown if the <paramref name="value"/> is null.</exception>
     public ProxySaveMappingSetting(T value, MatchBehaviour matchBehaviour = MatchBehaviour.AcceptOnMatch)
     {
-        Value = value;
+        Value = Guard.NotNull(value);
         MatchBehaviour = matchBehaviour;
     }
 
+    /// <summary>
+    /// Converts a non-nullable value of type <typeparamref name="T"/> to a <see cref="ProxySaveMappingSetting{T}"/> implicitly.
+    /// </summary>
+    /// <param name="value">The non-nullable value to convert.</param>
     public static implicit operator ProxySaveMappingSetting<T>(T value) => new(value);
 
-    public static implicit operator T(ProxySaveMappingSetting<T> @this) => @this.Value;
-}
+    /// <summary>
+    /// Converts a <see cref="ProxySaveMappingSetting{T}"/> to its underlying non-nullable value of type <typeparamref name="T"/> implicitly.
+    /// </summary>
+    /// <param name="instance">The <see cref="ProxySaveMappingSetting{T}"/> to convert.</param>
+    public static implicit operator T(ProxySaveMappingSetting<T> instance) => instance.Value;
+}