<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.1" />

System.Configuration.PropertyInformationCollection

Contains a collection of PropertyInformation objects. This class cannot be inherited.
namespace System.Configuration { public sealed class PropertyInformationCollection : NameObjectCollectionBase { public PropertyInformation this[string propertyName] { get; } internal PropertyInformation this[int index] { get; } public void CopyTo(PropertyInformation[] array, int index); } }