🎨 Usual nitpicky organizing usings and whatnot

Also used a method group.

Author: haacked

src/GitHub.App/Caches/CacheIndex.cs

@@ -1,11 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.Linq;
 using System.Reactive.Linq;
 using Akavache;
 using NullGuard;
-using System.Reactive;
-using System.Linq;
 
 namespace GitHub.Caches
 {

src/GitHub.App/Extensions/AkavacheExtensions.cs

@@ -1,9 +1,9 @@
 using System;
+using System.Linq;
+using System.Reactive;
 using System.Reactive.Linq;
 using Akavache;
 using GitHub.Caches;
-using System.Linq;
-using System.Reactive;
 
 namespace GitHub.Extensions
 {
@@ -222,7 +222,7 @@ static IObservable<T> GetAndFetchLatestFromIndex<T>(this IBlobCache This,
                             This.GetObjects<T>(index.OldKeys.Except(index.Keys))
                                 .Do(dict => This.InvalidateObjects<T>(dict.Keys))
                                 .SelectMany(dict => dict.Values)
-                                .Do(item => removedItemsCallback(item))
+                                .Do(removedItemsCallback)
                                 .Subscribe();
                         });
                 }));

src/GitHub.App/Services/ModelService.cs

@@ -8,14 +8,14 @@
 using Akavache;
 using GitHub.Api;
 using GitHub.Caches;
+using GitHub.Collections;
 using GitHub.Extensions;
 using GitHub.Extensions.Reactive;
 using GitHub.Models;
 using GitHub.Primitives;
 using NLog;
 using NullGuard;
 using Octokit;
-using GitHub.Collections;
 
 namespace GitHub.Services
 {

src/GitHub.Exports.Reactive/Collections/TrackingCollection.cs

@@ -9,7 +9,6 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Reactive;
 using System.Reactive.Concurrency;
 using System.Reactive.Disposables;