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

System.Configuration.ConfigurationSectionGroupCollection

Represents a collection of ConfigurationSectionGroup objects.
namespace System.Configuration { public sealed class ConfigurationSectionGroupCollection : NameObjectCollectionBase { public ConfigurationSectionGroup this[string name] { get; } public ConfigurationSectionGroup this[int index] { get; } public void Add(string name, ConfigurationSectionGroup sectionGroup); public void Clear(); public void CopyTo(ConfigurationSectionGroup[] array, int index); public ConfigurationSectionGroup Get(int index); public ConfigurationSectionGroup Get(string name); public string GetKey(int index); public void Remove(string name); public void RemoveAt(int index); } }