public ParcelEditToken ChangeParcelType( 
   ParcelLayer parcelLayer,
   SelectionSet sourceFeatures,
   Layer destinationPolygonLayer,
   Layer destinationLineLayer
)

//add polygon layers and the feature ids to change the type on to a new Dictionary
var ids = new List<long>(sourcePolygonL.GetSelection().GetObjectIDs());
var sourceFeatures = new Dictionary<MapMember, List<long>>
{
  { sourcePolygonL, ids }
};
try
{
  var editOper = new EditOperation()
  {
    Name = "Change Parcel Type",
    ProgressMessage = "Change Parcel Type...",
    ShowModalMessageAfterFailure = true,
    SelectNewFeatures = true,
    SelectModifiedFeatures = false
  };
  editOper.ChangeParcelType(myParcelFabricLayer, SelectionSet.FromDictionary(sourceFeatures), targetFeatLyr);
  if (!editOper.Execute())
    return editOper.ErrorMessage;
}
catch (Exception ex)
{
  return ex.Message;
}
return "";