namespace System.Configuration { public sealed class ClientSettingsSection : ConfigurationSection { private static ConfigurationPropertyCollection _properties; private static readonly ConfigurationProperty _propSettings; protected internal override ConfigurationPropertyCollection Properties => _properties; [ConfigurationProperty("", IsDefaultCollection = true)] public SettingElementCollection Settings { get { return (SettingElementCollection)base[_propSettings]; } } static ClientSettingsSection() { _propSettings = new ConfigurationProperty(null, typeof(SettingElementCollection), null, ConfigurationPropertyOptions.IsDefaultCollection); _properties = new ConfigurationPropertyCollection(); _properties.Add(_propSettings); } } }