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

System.Configuration.ConfigurationElementCollection

Represents a configuration element containing a collection of child elements.
namespace System.Configuration { public abstract class ConfigurationElementCollection : ConfigurationElement, ICollection, IEnumerable { public bool EmitClear { get; set; } protected virtual string ElementName { get; } protected virtual bool ThrowOnDuplicate { get; } public virtual ConfigurationElementCollectionType CollectionType { get; } public int Count { get; } public bool IsSynchronized { get; } public object SyncRoot { get; } protected ConfigurationElementCollection(); protected ConfigurationElementCollection(IComparer comparer); public IEnumerator GetEnumerator(); public void CopyTo(ConfigurationElement[] array, int index); protected virtual void BaseAdd(ConfigurationElement element); protected int BaseIndexOf(ConfigurationElement element); protected virtual void BaseAdd(int index, ConfigurationElement element); protected virtual ConfigurationElement CreateNewElement(string elementName); protected abstract ConfigurationElement CreateNewElement(); protected abstract object GetElementKey(ConfigurationElement element); protected virtual bool IsElementRemovable(ConfigurationElement element); protected virtual bool IsElementName(string elementName); } }