IdentitySeverのAddIdentityServerなにやっているのか？（工事中

public static IIdentityServerBuilder AddIdentityServer(this IServiceCollection services)
{
    var builder = services.AddIdentityServerBuilder();

    builder
        .AddRequiredPlatformServices()
        .AddCookieAuthentication()
        .AddCoreServices()
        .AddDefaultEndpoints()
        .AddPluggableServices()
        .AddKeyManagement()
        .AddDynamicProvidersCore()
        .AddOidcDynamicProvider()
        .AddValidators()
        .AddResponseGenerators()
        .AddDefaultSecretParsers()
        .AddDefaultSecretValidators();

    // provide default in-memory implementations, not suitable for most production scenarios
    builder.AddInMemoryPersistedGrants();
    builder.AddInMemoryPushedAuthorizationRequests();

    return builder;
}