in src/Amazon.Extensions.Configuration.SystemsManager/AppConfig/AppConfigExtensions.cs [201:208]
public static IConfigurationBuilder AddAppConfig(this IConfigurationBuilder builder, string applicationId, string environmentId, string configProfileId)
{
if (applicationId == null) throw new ArgumentNullException(nameof(applicationId));
if (environmentId == null) throw new ArgumentNullException(nameof(environmentId));
if (configProfileId == null) throw new ArgumentNullException(nameof(configProfileId));
return builder.AddAppConfig(ConfigureSource(applicationId, environmentId, configProfileId));
}