<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.5" />

System.Configuration.SettingsAttributeDictionary

Represents a collection of key/value pairs used to describe a configuration object as well as a SettingsProperty object.
namespace System.Configuration { public class SettingsAttributeDictionary : Hashtable { public SettingsAttributeDictionary(); public SettingsAttributeDictionary(SettingsAttributeDictionary attributes); protected SettingsAttributeDictionary(SerializationInfo serializationInfo, StreamingContext streamingContext); } }