public XPathAncestorIterator(XPathAncestorIterator other) : base(other) { }
		public XPathAncestorIterator(XPathAncestorIterator copy) : base (copy)
		{
			// TODO : do we need to clone this ?
			if(this.parents != null)
			{
				this.parents = (ArrayList)this.parents.Clone();
			}
		}