System.Xml.XPath.XPathNodeIterator.MoveNext C# (CSharp) Method

        public abstract bool MoveNext();
        public abstract XPathNavigator Current { get; }

		/// <summary>
		/// Implements the following function 
		///    number max(node-set)
		/// </summary>
		/// <param name="iterator"></param>
		/// <returns></returns>		
		public double max(XPathNodeIterator iterator)
		{
			double max, t;

			if (iterator.Count == 0)
			{
				return Double.NaN;
			}

			try
			{

				iterator.MoveNext();
				max = XmlConvert.ToDouble(iterator.Current.Value);

				while (iterator.MoveNext())
				{
					t = XmlConvert.ToDouble(iterator.Current.Value);
					max = (t > max) ? t : max;
				}

			}
			catch
			{
				return Double.NaN;
			}

			return max;
		}