bool ICollection <T?> .Remove(T?node) => throw ThrowHelper.NotSupportedException_NodeCollectionIsReadOnly();
 public void Clear() => throw ThrowHelper.NotSupportedException_NodeCollectionIsReadOnly();
 bool ICollection <string> .Remove(string propertyName) => throw ThrowHelper.NotSupportedException_NodeCollectionIsReadOnly();
 public void Add(T?jsonNode) => throw ThrowHelper.NotSupportedException_NodeCollectionIsReadOnly();
 public void Add(string propertyName) => throw ThrowHelper.NotSupportedException_NodeCollectionIsReadOnly();