<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.0-preview.7.25380.108" />

System.Configuration.NameValueSectionHandler

Provides name/value-pair configuration information from a configuration section.
namespace System.Configuration { public class NameValueSectionHandler : IConfigurationSectionHandler { protected virtual string KeyAttributeName { get; } protected virtual string ValueAttributeName { get; } public object Create(object parent, object context, XmlNode section); public NameValueSectionHandler(); } }