diff --git a/src/AbpDesk/AbpDesk.Application/AbpDesk/Tickets/TicketAppService.cs b/src/AbpDesk/AbpDesk.Application/AbpDesk/Tickets/TicketAppService.cs
index db62a39d24..f0333ef3f0 100644
--- a/src/AbpDesk/AbpDesk.Application/AbpDesk/Tickets/TicketAppService.cs
+++ b/src/AbpDesk/AbpDesk.Application/AbpDesk/Tickets/TicketAppService.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using AbpDesk.Tickets.Dtos;
@@ -7,7 +8,6 @@ using Volo.Abp.Application.Services.Dtos;
 using Volo.Abp.Domain.Repositories;
 using Volo.Abp.Linq;
 using Volo.Abp.Linq.Extensions;
-using Volo.ExtensionMethods;
 
 namespace AbpDesk.Tickets
 {
diff --git a/src/AbpDesk/AbpDesk.MongoBlog/AbpDesk/Blogging/BlogPost.cs b/src/AbpDesk/AbpDesk.MongoBlog/AbpDesk/Blogging/BlogPost.cs
index 5a155d987f..3ae4b3f678 100644
--- a/src/AbpDesk/AbpDesk.MongoBlog/AbpDesk/Blogging/BlogPost.cs
+++ b/src/AbpDesk/AbpDesk.MongoBlog/AbpDesk/Blogging/BlogPost.cs
@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using JetBrains.Annotations;
 using Volo;
 using Volo.Abp.Domain.Entities;
-using Volo.ExtensionMethods;
 
 namespace AbpDesk.Blogging
 {
diff --git a/src/AbpDesk/Web_PlugIns/AbpDesk.MongoBlog.dll b/src/AbpDesk/Web_PlugIns/AbpDesk.MongoBlog.dll
index f7ed13b4ce..95cabe3c23 100644
Binary files a/src/AbpDesk/Web_PlugIns/AbpDesk.MongoBlog.dll and b/src/AbpDesk/Web_PlugIns/AbpDesk.MongoBlog.dll differ
diff --git a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/DomainTenantResolver.cs b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/DomainTenantResolver.cs
index 2ee7d7edcf..48ab8981b9 100644
--- a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/DomainTenantResolver.cs
+++ b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/DomainTenantResolver.cs
@@ -1,7 +1,7 @@
-using Microsoft.AspNetCore.Http;
+using System;
+using Microsoft.AspNetCore.Http;
 using Volo.Abp.MultiTenancy;
 using Volo.Abp.Text.Formatting;
-using Volo.ExtensionMethods;
 
 namespace Volo.Abp.AspNetCore.MultiTenancy
 {
diff --git a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HeaderTenantResolver.cs b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HeaderTenantResolver.cs
index 1a68fc9a35..c5f1385c0c 100644
--- a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HeaderTenantResolver.cs
+++ b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HeaderTenantResolver.cs
@@ -1,9 +1,9 @@
-using System.Linq;
+using System.Collections.Generic;
+using System.Linq;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Volo.Abp.MultiTenancy;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AspNetCore.MultiTenancy
 {
diff --git a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HttpTenantResolverBase.cs b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HttpTenantResolverBase.cs
index 62f72dc36c..aae63eef8d 100644
--- a/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HttpTenantResolverBase.cs
+++ b/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/HttpTenantResolverBase.cs
@@ -4,7 +4,6 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Volo.Abp.MultiTenancy;
-using Volo.ExtensionMethods;
 
 namespace Volo.Abp.AspNetCore.MultiTenancy
 {
diff --git a/src/Volo.Abp.AspNetCore.Mvc.UI/Bundling/BundleCollection.cs b/src/Volo.Abp.AspNetCore.Mvc.UI/Bundling/BundleCollection.cs
index a56b088361..c52e2ac406 100644
--- a/src/Volo.Abp.AspNetCore.Mvc.UI/Bundling/BundleCollection.cs
+++ b/src/Volo.Abp.AspNetCore.Mvc.UI/Bundling/BundleCollection.cs
@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AspNetCore.Mvc.Bundling
 {
diff --git a/src/Volo.Abp.AspNetCore.TestBase/Volo/Abp/AspNetCore/TestBase/AbpAspNetCoreIntegratedTestBase.cs b/src/Volo.Abp.AspNetCore.TestBase/Volo/Abp/AspNetCore/TestBase/AbpAspNetCoreIntegratedTestBase.cs
index 4dac052314..4f9da35c91 100644
--- a/src/Volo.Abp.AspNetCore.TestBase/Volo/Abp/AspNetCore/TestBase/AbpAspNetCoreIntegratedTestBase.cs
+++ b/src/Volo.Abp.AspNetCore.TestBase/Volo/Abp/AspNetCore/TestBase/AbpAspNetCoreIntegratedTestBase.cs
@@ -1,11 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.AspNetCore.TestHost;
-using Volo.ExtensionMethods;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AspNetCore.TestBase
 {
diff --git a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapAttribute.cs b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapAttribute.cs
index f5284776fc..e0fcf06d05 100644
--- a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapAttribute.cs
+++ b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapAttribute.cs
@@ -1,6 +1,6 @@
 using System;
+using System.Collections.Generic;
 using AutoMapper;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AutoMapper
 {
diff --git a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapFromAttribute.cs b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapFromAttribute.cs
index 9d0c765559..5e767273e1 100644
--- a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapFromAttribute.cs
+++ b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapFromAttribute.cs
@@ -1,6 +1,6 @@
 using System;
+using System.Collections.Generic;
 using AutoMapper;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AutoMapper
 {
diff --git a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapToAttribute.cs b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapToAttribute.cs
index a0f3e4e26f..9b42fd4f46 100644
--- a/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapToAttribute.cs
+++ b/src/Volo.Abp.AutoMapper/Volo/Abp/AutoMapper/AutoMapToAttribute.cs
@@ -1,6 +1,6 @@
 using System;
+using System.Collections.Generic;
 using AutoMapper;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.AutoMapper
 {
diff --git a/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextOptionsFactory.cs b/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextOptionsFactory.cs
index 6f1c7de208..29a9572977 100644
--- a/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextOptionsFactory.cs
+++ b/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextOptionsFactory.cs
@@ -1,9 +1,9 @@
 using System;
+using System.Collections.Generic;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using Volo.Abp.Data;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.EntityFrameworkCore.DependencyInjection
 {
diff --git a/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityRole.cs b/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityRole.cs
index 58302389cc..590598d48d 100644
--- a/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityRole.cs
+++ b/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityRole.cs
@@ -5,7 +5,6 @@ using System.Security.Claims;
 using JetBrains.Annotations;
 using Volo.Abp.Domain.Entities;
 using Volo.Abp.Guids;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Identity
 {
diff --git a/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityUser.cs b/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityUser.cs
index d30cbac50a..c1df7ba87e 100644
--- a/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityUser.cs
+++ b/src/Volo.Abp.Identity/Volo/Abp/Identity/IdentityUser.cs
@@ -7,7 +7,6 @@ using JetBrains.Annotations;
 using Microsoft.AspNetCore.Identity;
 using Volo.Abp.Domain.Entities;
 using Volo.Abp.Guids;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Identity
 {
diff --git a/src/Volo.Abp.MongoDB/Volo/Abp/MongoDB/AbpMongoDbContext.cs b/src/Volo.Abp.MongoDB/Volo/Abp/MongoDB/AbpMongoDbContext.cs
index 25b086d908..841b8ca264 100644
--- a/src/Volo.Abp.MongoDB/Volo/Abp/MongoDB/AbpMongoDbContext.cs
+++ b/src/Volo.Abp.MongoDB/Volo/Abp/MongoDB/AbpMongoDbContext.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.MongoDB
 {
diff --git a/src/Volo.Abp.MultiTenancy/Volo/Abp/Data/MultiTenancy/MultiTenantConnectionStringResolver.cs b/src/Volo.Abp.MultiTenancy/Volo/Abp/Data/MultiTenancy/MultiTenantConnectionStringResolver.cs
index 1ac6bbfcd2..5967f630ca 100644
--- a/src/Volo.Abp.MultiTenancy/Volo/Abp/Data/MultiTenancy/MultiTenantConnectionStringResolver.cs
+++ b/src/Volo.Abp.MultiTenancy/Volo/Abp/Data/MultiTenancy/MultiTenantConnectionStringResolver.cs
@@ -1,7 +1,7 @@
-using Microsoft.Extensions.Options;
+using System.Collections.Generic;
+using Microsoft.Extensions.Options;
 using Volo.Abp.MultiTenancy;
 using Volo.DependencyInjection;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Data.MultiTenancy
 {
diff --git a/src/Volo.Abp/System/AbpComparableExtensions.cs b/src/Volo.Abp/System/AbpComparableExtensions.cs
index c708231b97..c21b17c920 100644
--- a/src/Volo.Abp/System/AbpComparableExtensions.cs
+++ b/src/Volo.Abp/System/AbpComparableExtensions.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for <see cref="IComparable{T}"/>.
diff --git a/src/Volo.Abp/System/AbpDayOfWeekExtensions.cs b/src/Volo.Abp/System/AbpDayOfWeekExtensions.cs
index ee954ea67d..fcc3085011 100644
--- a/src/Volo.Abp/System/AbpDayOfWeekExtensions.cs
+++ b/src/Volo.Abp/System/AbpDayOfWeekExtensions.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for <see cref="AbpDayOfWeekExtensions"/>.
diff --git a/src/Volo.Abp/System/AbpEventHandlerExtensions.cs b/src/Volo.Abp/System/AbpEventHandlerExtensions.cs
index 459c405d7a..5c184f32de 100644
--- a/src/Volo.Abp/System/AbpEventHandlerExtensions.cs
+++ b/src/Volo.Abp/System/AbpEventHandlerExtensions.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for <see cref="EventHandler"/>.
diff --git a/src/Volo.Abp/System/AbpExceptionExtensions.cs b/src/Volo.Abp/System/AbpExceptionExtensions.cs
index be677b91da..c3a5baaa96 100644
--- a/src/Volo.Abp/System/AbpExceptionExtensions.cs
+++ b/src/Volo.Abp/System/AbpExceptionExtensions.cs
@@ -1,7 +1,6 @@
-using System;
 using System.Runtime.ExceptionServices;
 
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for <see cref="Exception"/> class.
diff --git a/src/Volo.Abp/System/AbpObjectExtensions.cs b/src/Volo.Abp/System/AbpObjectExtensions.cs
index 80e16e25c6..36896ea59a 100644
--- a/src/Volo.Abp/System/AbpObjectExtensions.cs
+++ b/src/Volo.Abp/System/AbpObjectExtensions.cs
@@ -1,8 +1,7 @@
-using System;
-using System.Globalization;
+using System.Globalization;
 using System.Linq;
 
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for all objects.
diff --git a/src/Volo.Abp/System/AbpStringExtensions.cs b/src/Volo.Abp/System/AbpStringExtensions.cs
index b960ee218a..73c9b6aad9 100644
--- a/src/Volo.Abp/System/AbpStringExtensions.cs
+++ b/src/Volo.Abp/System/AbpStringExtensions.cs
@@ -1,10 +1,10 @@
-using System;
+using System.Collections.Generic;
 using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
-using Volo.ExtensionMethods.Collections.Generic;
+using Volo;
 
-namespace Volo.ExtensionMethods
+namespace System
 {
     /// <summary>
     /// Extension methods for String class.
diff --git a/src/Volo.Abp/System/Collections/Generic/AbpCollectionExtensions.cs b/src/Volo.Abp/System/Collections/Generic/AbpCollectionExtensions.cs
index 66693d266c..a2f82d6de8 100644
--- a/src/Volo.Abp/System/Collections/Generic/AbpCollectionExtensions.cs
+++ b/src/Volo.Abp/System/Collections/Generic/AbpCollectionExtensions.cs
@@ -1,9 +1,8 @@
-using System;
-using System.Collections.Generic;
 using System.Linq;
 using JetBrains.Annotations;
+using Volo;
 
-namespace Volo.ExtensionMethods.Collections.Generic
+namespace System.Collections.Generic
 {
     /// <summary>
     /// Extension methods for Collections.
diff --git a/src/Volo.Abp/System/Collections/Generic/AbpDictionaryExtensions.cs b/src/Volo.Abp/System/Collections/Generic/AbpDictionaryExtensions.cs
index 48c78a2f38..47ceca79f2 100644
--- a/src/Volo.Abp/System/Collections/Generic/AbpDictionaryExtensions.cs
+++ b/src/Volo.Abp/System/Collections/Generic/AbpDictionaryExtensions.cs
@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-
-namespace Volo.ExtensionMethods.Collections.Generic
+namespace System.Collections.Generic
 {
     /// <summary>
     /// Extension methods for Dictionary.
diff --git a/src/Volo.Abp/System/Collections/Generic/AbpEnumerableExtensions.cs b/src/Volo.Abp/System/Collections/Generic/AbpEnumerableExtensions.cs
index edee9c15d4..0aaed99b81 100644
--- a/src/Volo.Abp/System/Collections/Generic/AbpEnumerableExtensions.cs
+++ b/src/Volo.Abp/System/Collections/Generic/AbpEnumerableExtensions.cs
@@ -1,8 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
+using System.Linq;
 
-namespace Volo.ExtensionMethods.Collections.Generic
+namespace System.Collections.Generic
 {    
     /// <summary> 
     /// Extension methods for <see cref="IEnumerable{T}"/>.
diff --git a/src/Volo.Abp/System/Collections/Generic/AbpListExtensions.cs b/src/Volo.Abp/System/Collections/Generic/AbpListExtensions.cs
index 9dbbf0496d..5ad63cc82c 100644
--- a/src/Volo.Abp/System/Collections/Generic/AbpListExtensions.cs
+++ b/src/Volo.Abp/System/Collections/Generic/AbpListExtensions.cs
@@ -1,9 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
+using System.Linq;
 using JetBrains.Annotations;
+using Volo;
 
-namespace Volo.ExtensionMethods.Collections.Generic
+namespace System.Collections.Generic
 {
     /// <summary>
     /// Extension methods for <see cref="IList{T}"/>.
diff --git a/src/Volo.Abp/System/IO/AbpStreamExtensions.cs b/src/Volo.Abp/System/IO/AbpStreamExtensions.cs
index e8f05cece9..88cf61b48e 100644
--- a/src/Volo.Abp/System/IO/AbpStreamExtensions.cs
+++ b/src/Volo.Abp/System/IO/AbpStreamExtensions.cs
@@ -1,6 +1,4 @@
-using System.IO;
-
-namespace Volo.ExtensionMethods
+namespace System.IO
 {
     public static class AbpStreamExtensions
     {
diff --git a/src/Volo.Abp/Volo/Abp/Check.cs b/src/Volo.Abp/Volo/Abp/Check.cs
index 37fa30ea7e..c8877569db 100644
--- a/src/Volo.Abp/Volo/Abp/Check.cs
+++ b/src/Volo.Abp/Volo/Abp/Check.cs
@@ -2,8 +2,6 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using JetBrains.Annotations;
-using Volo.ExtensionMethods;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo
 {
diff --git a/src/Volo.Abp/Volo/Abp/Data/ConnectionStrings.cs b/src/Volo.Abp/Volo/Abp/Data/ConnectionStrings.cs
index d2df90c809..a72f9a079e 100644
--- a/src/Volo.Abp/Volo/Abp/Data/ConnectionStrings.cs
+++ b/src/Volo.Abp/Volo/Abp/Data/ConnectionStrings.cs
@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Data
 {
diff --git a/src/Volo.Abp/Volo/Abp/Data/DefaultConnectionStringResolver.cs b/src/Volo.Abp/Volo/Abp/Data/DefaultConnectionStringResolver.cs
index 79f152000d..2fb44348ce 100644
--- a/src/Volo.Abp/Volo/Abp/Data/DefaultConnectionStringResolver.cs
+++ b/src/Volo.Abp/Volo/Abp/Data/DefaultConnectionStringResolver.cs
@@ -1,7 +1,7 @@
+using System;
+using System.Collections.Generic;
 using Microsoft.Extensions.Options;
 using Volo.DependencyInjection;
-using Volo.ExtensionMethods;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Data
 {
diff --git a/src/Volo.Abp/Volo/Abp/DependencyInjection/AutoRegistrationHelper.cs b/src/Volo.Abp/Volo/Abp/DependencyInjection/AutoRegistrationHelper.cs
index 01228981e9..513edb7e71 100644
--- a/src/Volo.Abp/Volo/Abp/DependencyInjection/AutoRegistrationHelper.cs
+++ b/src/Volo.Abp/Volo/Abp/DependencyInjection/AutoRegistrationHelper.cs
@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using Microsoft.Extensions.DependencyInjection;
-using Volo.ExtensionMethods;
 
 namespace Volo.DependencyInjection
 {
diff --git a/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileManager.cs b/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileManager.cs
index d21dfe5586..82359299ec 100644
--- a/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileManager.cs
+++ b/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileManager.cs
@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using Microsoft.Extensions.Options;
 using Volo.DependencyInjection;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.EmbeddedFiles
 {
diff --git a/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileSet.cs b/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileSet.cs
index 8dccf42f33..14981250b5 100644
--- a/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileSet.cs
+++ b/src/Volo.Abp/Volo/Abp/EmbeddedFiles/EmbeddedFileSet.cs
@@ -1,9 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Reflection;
-using Volo.ExtensionMethods;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.EmbeddedFiles
 {
diff --git a/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleDescriptor.cs b/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleDescriptor.cs
index 87ce07cffa..a4b679d5ee 100644
--- a/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleDescriptor.cs
+++ b/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleDescriptor.cs
@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Reflection;
 using JetBrains.Annotations;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Modularity
 {
diff --git a/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleHelper.cs b/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleHelper.cs
index 5bac844ada..f13d21a9d2 100644
--- a/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleHelper.cs
+++ b/src/Volo.Abp/Volo/Abp/Modularity/AbpModuleHelper.cs
@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Modularity
 {
diff --git a/src/Volo.Abp/Volo/Abp/Modularity/ModuleLoader.cs b/src/Volo.Abp/Volo/Abp/Modularity/ModuleLoader.cs
index 00f8c6e093..4c28f2b316 100644
--- a/src/Volo.Abp/Volo/Abp/Modularity/ModuleLoader.cs
+++ b/src/Volo.Abp/Volo/Abp/Modularity/ModuleLoader.cs
@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.Modularity.PlugIns;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Modularity
 {
diff --git a/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FilePlugInSource.cs b/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FilePlugInSource.cs
index 65475abc9a..f818c74109 100644
--- a/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FilePlugInSource.cs
+++ b/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FilePlugInSource.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Runtime.Loader;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Modularity.PlugIns
 {
diff --git a/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FolderPlugInSource.cs b/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FolderPlugInSource.cs
index 043f552593..b0544d0338 100644
--- a/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FolderPlugInSource.cs
+++ b/src/Volo.Abp/Volo/Abp/Modularity/PlugIns/FolderPlugInSource.cs
@@ -6,7 +6,6 @@ using System.Reflection;
 using System.Runtime.Loader;
 using JetBrains.Annotations;
 using Volo.Abp.Reflection;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Modularity.PlugIns
 {
diff --git a/src/Volo.Abp/Volo/Abp/Text/Formatting/FormattedStringValueExtracter.cs b/src/Volo.Abp/Volo/Abp/Text/Formatting/FormattedStringValueExtracter.cs
index 6008836501..6d21fc2a73 100644
--- a/src/Volo.Abp/Volo/Abp/Text/Formatting/FormattedStringValueExtracter.cs
+++ b/src/Volo.Abp/Volo/Abp/Text/Formatting/FormattedStringValueExtracter.cs
@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Text.Formatting
 {
diff --git a/src/Volo.Abp/Volo/Abp/Ui/Navigation/ApplicationMenuItem.cs b/src/Volo.Abp/Volo/Abp/Ui/Navigation/ApplicationMenuItem.cs
index dc2f4d5547..354cfd3b00 100644
--- a/src/Volo.Abp/Volo/Abp/Ui/Navigation/ApplicationMenuItem.cs
+++ b/src/Volo.Abp/Volo/Abp/Ui/Navigation/ApplicationMenuItem.cs
@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using JetBrains.Annotations;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.UI.Navigation
 {
diff --git a/src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs b/src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs
index a5794af42e..47dc909581 100644
--- a/src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs
+++ b/src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs
@@ -2,7 +2,6 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
-using Volo.ExtensionMethods;
 
 namespace Volo.Abp.Uow
 {
diff --git a/src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs b/src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs
index f128c7d470..841fefe039 100644
--- a/src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs
+++ b/src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs
@@ -3,8 +3,6 @@ using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Volo.DependencyInjection;
-using Volo.ExtensionMethods;
-using Volo.ExtensionMethods.Collections.Generic;
 
 namespace Volo.Abp.Uow
 {
diff --git a/test/Volo.Abp.Tests/Volo/Abp/Text/Formatting/FormattedStringTokenizer_Test.cs b/test/Volo.Abp.Tests/Volo/Abp/Text/Formatting/FormattedStringTokenizer_Test.cs
index 4a69a01f6a..c34f292c27 100644
--- a/test/Volo.Abp.Tests/Volo/Abp/Text/Formatting/FormattedStringTokenizer_Test.cs
+++ b/test/Volo.Abp.Tests/Volo/Abp/Text/Formatting/FormattedStringTokenizer_Test.cs
@@ -1,6 +1,6 @@
 using System;
 using Shouldly;
-using Volo.ExtensionMethods.Collections.Generic;
+using System.Collections.Generic;
 using Xunit;
 
 namespace Volo.Abp.Text.Formatting
diff --git a/test/Volo.Abp.Tests/Volo/Abp/Ui/Navigation/MenuManager_Tests.cs b/test/Volo.Abp.Tests/Volo/Abp/Ui/Navigation/MenuManager_Tests.cs
index 346b5d83ec..1c7859172a 100644
--- a/test/Volo.Abp.Tests/Volo/Abp/Ui/Navigation/MenuManager_Tests.cs
+++ b/test/Volo.Abp.Tests/Volo/Abp/Ui/Navigation/MenuManager_Tests.cs
@@ -3,7 +3,7 @@ using Microsoft.Extensions.DependencyInjection;
 using Shouldly;
 using Volo.Abp.Modularity;
 using Volo.Abp.TestBase;
-using Volo.ExtensionMethods.Collections.Generic;
+using System.Collections.Generic;
 using Xunit;
 
 namespace Volo.Abp.UI.Navigation