Refactored.

src/Volo.Abp.AspNetCore/Volo/Abp/ServiceProviderAccessorExtensions.cs

@@ -1,6 +1,7 @@
 using JetBrains.Annotations;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
+using Volo.Abp.DependencyInjection;
 
 namespace Volo.Abp
 {

src/Volo.Abp.MultiTenancy/Volo/Abp/MultiTenancy/ICurrentTenantResolveContext.cs

@@ -1,3 +1,5 @@
+using Volo.Abp.DependencyInjection;
+
 namespace Volo.Abp.MultiTenancy
 {
     public interface ICurrentTenantResolveContext : IServiceProviderAccessor

src/Volo.Abp/Volo/Abp/AbpApplication.cs

@@ -8,10 +8,12 @@ namespace Volo.Abp
 {
     public class AbpApplication
     {
+        [NotNull]
         public Type StartupModuleType { get; }
 
         public IServiceProvider ServiceProvider { get; private set; }
 
+        [NotNull]
         internal AbpModuleDescriptor[] Modules { get; }
 
         private AbpApplication(
@@ -65,7 +67,10 @@ namespace Volo.Abp
             Check.NotNull(serviceProvider, nameof(serviceProvider));
 
             ServiceProvider = serviceProvider;
-            ServiceProvider.GetRequiredService<IModuleManager>().InitializeModules(new ApplicationInitializationContext(serviceProvider));
+
+            ServiceProvider
+                .GetRequiredService<IModuleManager>()
+                .InitializeModules(new ApplicationInitializationContext(serviceProvider));
         }
 
         private AbpModuleDescriptor[] LoadModules(IServiceCollection services, AbpApplicationCreationOptions options)
@@ -81,7 +86,9 @@ namespace Volo.Abp
 
         public void Shutdown()
         {
-            ServiceProvider.GetRequiredService<IModuleManager>().ShutdownModules(new ApplicationShutdownContext());
+            ServiceProvider
+                .GetRequiredService<IModuleManager>()
+                .ShutdownModules(new ApplicationShutdownContext());
         }
     }
 }

src/Volo.Abp/Volo/Abp/AbpApplicationCreationOptions.cs

@@ -1,9 +1,11 @@
+using JetBrains.Annotations;
 using Volo.Abp.Modularity.PlugIns;
 
 namespace Volo.Abp
 {
     public class AbpApplicationCreationOptions
     {
+        [NotNull]
         public PlugInSourceList PlugInSources { get; private set; }
 
         public AbpApplicationCreationOptions()

src/Volo.Abp/Volo/Abp/DependencyInjection/IServiceProviderAccessor.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace Volo.Abp.DependencyInjection
+{
+    public interface IServiceProviderAccessor //TODO: Move to Volo.DependencyInjection package?
+    {
+        IServiceProvider ServiceProvider { get; }
+    }
+}

src/Volo.Abp/Volo/Abp/IServiceProviderAccessor.cs

@@ -1,9 +0,0 @@
-using System;
-
-namespace Volo.Abp
-{
-    public interface IServiceProviderAccessor
-    {
-        IServiceProvider ServiceProvider { get; }
-    }
-}

src/Volo.Abp/Volo/Abp/Modularity/ModuleLoader.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.Modularity.PlugIns;
 using Volo.ExtensionMethods.Collections.Generic;
@@ -10,8 +9,10 @@ namespace Volo.Abp.Modularity
 {
     public class ModuleLoader : IModuleLoader
     {
-        [NotNull]
+        public AbpModuleDescriptor[] LoadModules(
-        public AbpModuleDescriptor[] LoadModules([NotNull] IServiceCollection services, [NotNull] Type startupModuleType, [NotNull] PlugInSourceList plugInSources)
+            IServiceCollection services, 
+            Type startupModuleType, 
+            PlugInSourceList plugInSources)
         {
             Check.NotNull(services, nameof(services));
             Check.NotNull(startupModuleType, nameof(startupModuleType));
@@ -27,7 +28,11 @@ namespace Volo.Abp.Modularity
             return modules.ToArray();
         }
 
-        protected virtual void FillModules(List<AbpModuleDescriptor> modules, IServiceCollection services, Type startupModuleType, PlugInSourceList plugInSources)
+        protected virtual void FillModules(
+            List<AbpModuleDescriptor> modules, 
+            IServiceCollection services, 
+            Type startupModuleType, 
+            PlugInSourceList plugInSources)
         {
             //All modules starting from the startup module
             var moduleTypes = AbpModuleHelper.FindAllModuleTypes(startupModuleType);

src/Volo.Abp/Volo/Abp/Uow/IUnitOfWork.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
+using Volo.Abp.DependencyInjection;
 using Volo.DependencyInjection;
 
 namespace Volo.Abp.Uow