XPath structur as input and result

In the following a mapping function which gets the root node of the document, reads the document structure from it and then returns an XPath structure.

namespace eBiss
{
    public class Excel : IMapFunctionExtender
    {
        [MappingFunction]
        public XPathNodeIterator ConvertLine(System.Xml.XPath.XPathNodeIterator itc)
        {
            XPathNodeIterator returnValue = null;
            if (itc != null && itc.MoveNext() == true)
            {
                eBiss.Api.XPath.PathNavigator pathNavigator = (eBiss.Api.XPath.PathNavigator)itc.Current;
 
                Dampfturbine_Meldedaten meldedaten = (Dampfturbine_Meldedaten) pathNavigator.CurrentInstance;
 
                MachinesRoot machineTypeRoot = new MachinesRoot(meldedaten);
 
                returnValue = machineTypeRoot.AsPathNodeIterator()
            }
 
            return returnValue;
        }
    }
 
    internal class PropertyGroup : IMapObjectRoot
    {
        public List<HapProperty> Property { get; set; } = new List<HapProperty>();
    }
 
 
    internal class HapProperty : IMapObjectItem
    {
        public string Value { get; set; }
        public string Type { get; set; }
    }
 
}