udpate feed and get pref

i think. i don't know any prefs to check.

ttrss/ApiClient.cs

@@ -505,15 +505,44 @@ namespace ttrss_co_client.ttrss
         ///<summary>
         ///tell the feed to update. As opposed to updating our configuration of the feed.
         ///</summary>
-        public async Task UpdateFeed(int feed_id)
+        public async Task<bool> UpdateFeed(int feed_id)
         {
             assertInitialized();
-            throw new NotImplementedException();
+
+            var json = JsonContent.Create(new
+            {
+                op = "updateFeed",
+                sid = this.SessionId,
+                feed_id = feed_id
+            });
+            var apiResponse = await get<Dictionary<string, string>>(json);
+            
+            return apiResponse.ContainsKey("status") && apiResponse["status"]?.ToLower() == "ok";
         }
-        public async Task<string> GetPref(string key)
+        public async Task<T> GetPref<T>(string pref)
         {
             assertInitialized();
-            throw new NotImplementedException();
+
+            var json = JsonContent.Create(new
+            {
+                op = "getPref",
+                sid = this.SessionId,
+                pref_name = pref
+            });
+            var apiResponse = await get<Dictionary<string, string>>(json);
+            try
+            {
+                var converter = TypeDescriptor.GetConverter(typeof(T));
+                if (converter != null)
+                {
+                    return (T)converter.ConvertFromString(apiResponse["value"]);
+                }
+                return default(T);
+            }
+            catch (NotSupportedException)
+            {
+                return default(T);
+            }
         }
         public enum CATCHUPMODE { All, OneDay, OneWeek, TwoWeeks }
         public async Task CatchupFeed(int feed_id, bool is_cat, CATCHUPMODE mode = CATCHUPMODE.All)