Remove unnecessary overloads.

src/Volo.Abp/Microsoft/Extensions/DependencyInjection/ServiceCollectionApplicationExtensions.cs

@@ -7,32 +7,18 @@ namespace Microsoft.Extensions.DependencyInjection
 {
     public static class ServiceCollectionApplicationExtensions
     {
-        public static IAbpApplicationWithExternalServiceProvider AddApplication<TStartupModule>(
-            [NotNull] this IServiceCollection services)
-            where TStartupModule : IAbpModule
-        {
-            return AbpApplicationFactory.Create<TStartupModule>(services);
-        }
-
         public static IAbpApplicationWithExternalServiceProvider AddApplication<TStartupModule>(
             [NotNull] this IServiceCollection services, 
-            [CanBeNull] Action<AbpApplicationCreationOptions> optionsAction)
+            [CanBeNull] Action<AbpApplicationCreationOptions> optionsAction = null)
             where TStartupModule : IAbpModule
         {
             return AbpApplicationFactory.Create<TStartupModule>(services, optionsAction);
         }
 
-        public static IAbpApplicationWithExternalServiceProvider AddApplication(
-            [NotNull] this IServiceCollection services,
-            [NotNull] Type startupModuleType)
-        {
-            return AbpApplicationFactory.Create(startupModuleType, services);
-        }
-
         public static IAbpApplicationWithExternalServiceProvider AddApplication(
             [NotNull] this IServiceCollection services,
             [NotNull] Type startupModuleType,
-            [CanBeNull] Action<AbpApplicationCreationOptions> optionsAction)
+            [CanBeNull] Action<AbpApplicationCreationOptions> optionsAction = null)
         {
             return AbpApplicationFactory.Create(startupModuleType, services, optionsAction);
         }