chore: adds headers to EventSourceServiceUnsuccessfulResponseException

src/LaunchDarkly.EventSource/EventSourceService.cs

@@ -256,7 +256,7 @@ private void ValidateResponse(HttpResponseMessage response)
             // Any non-2xx response status is an error. A 204 (no content) is also an error.
             if (!response.IsSuccessStatusCode || response.StatusCode == System.Net.HttpStatusCode.NoContent)
             {
-                throw new EventSourceServiceUnsuccessfulResponseException((int)response.StatusCode);
+                throw new EventSourceServiceUnsuccessfulResponseException((int)response.StatusCode, response.Headers);
             }
 
             if (response.Content == null)

src/LaunchDarkly.EventSource/EventSourceServiceUnsuccessfulResponseException.cs

@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 
 namespace LaunchDarkly.EventSource
 {
@@ -14,6 +15,11 @@ public class EventSourceServiceUnsuccessfulResponseException : EventSourceServic
         /// </summary>
         public int StatusCode { get; }
 
+        /// <summary>
+        /// The HTTP headers from the response.
+        /// </summary>
+        public IEnumerable<KeyValuePair<string, IEnumerable<string>>> Headers { get; }
+
         #endregion
 
         #region Public Constructors 
@@ -23,9 +29,20 @@ public class EventSourceServiceUnsuccessfulResponseException : EventSourceServic
         /// </summary>
         /// <param name="statusCode">the HTTP status code of the response</param>
         public EventSourceServiceUnsuccessfulResponseException(int statusCode) :
+            this(statusCode, new Dictionary<string, IEnumerable<string>>())
+        {
+        }
+
+        /// <summary>
+        /// Creates a new instance with headers.
+        /// </summary>
+        /// <param name="statusCode">the HTTP status code of the response</param>
+        /// <param name="headers">the HTTP headers from the response</param>
+        public EventSourceServiceUnsuccessfulResponseException(int statusCode, IEnumerable<KeyValuePair<string, IEnumerable<string>>> headers) :
             base(string.Format(Resources.ErrorHttpStatus, statusCode))
         {
             StatusCode = statusCode;
+            Headers = headers ?? new Dictionary<string, IEnumerable<string>>();
         }
 
         #endregion