public enum AttributeFlags : System.Enum, System.IComparable, System.IConvertible, System.IFormattable, System.ISpanFormattable  

// list of points
List<MapPoint> points = new List<MapPoint>
{
  MapPointBuilderEx.CreateMapPoint(0, 0, 2, 3, 1),
  MapPointBuilderEx.CreateMapPoint(1, 1, 5, 6),
  MapPointBuilderEx.CreateMapPoint(2, 1, 6),
  MapPointBuilderEx.CreateMapPoint(0, 0)
};

// will have attributes because it is created with convenience method
Polyline polylineWithAttrs = PolylineBuilderEx.CreatePolyline(points);
bool hasZ = polylineWithAttrs.HasZ;          // hasZ = true
bool hasM = polylineWithAttrs.HasM;          // hasM = true
bool hasID = polylineWithAttrs.HasID;        // hasID = true

// will not have attributes because it is specified as a parameter
Polyline polylineWithoutAttrs = 
  PolylineBuilderEx.CreatePolyline(points, AttributeFlags.None);
hasZ = polylineWithoutAttrs.HasZ;          // hasZ = false
hasM = polylineWithoutAttrs.HasM;          // hasM = false
hasID = polylineWithoutAttrs.HasID;        // hasID = false

// will have attributes because it is created with convenience method
Polygon polygonWithAttrs = PolygonBuilderEx.CreatePolygon(points);
hasZ = polygonWithAttrs.HasZ;               // hasZ = true
hasM = polygonWithAttrs.HasM;               // hasM = true
hasID = polygonWithAttrs.HasID;             // hasID = true

// will not have attributes because it is specified as a parameter
Polygon polygonWithoutAttrs = 
      PolygonBuilderEx.CreatePolygon(points, AttributeFlags.None);
hasZ = polygonWithoutAttrs.HasZ;               // hasZ = false
hasM = polygonWithoutAttrs.HasM;               // hasM = false
hasID = polygonWithoutAttrs.HasID;             // hasID = false

// will not have attributes because it is specified as a parameter
PolylineBuilderEx polylineB = 
           new PolylineBuilderEx(points, AttributeFlags.None);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will have attributes because it is passed an attributed polyline
polylineB = new PolylineBuilderEx(polylineWithAttrs);
hasZ = polylineB.HasZ;                      // hasZ = true
hasM = polylineB.HasM;                      // hasM = true
hasID = polylineB.HasID;                    // hasID = true

// will not have attributes because it is passed a non-attributed polyline
polylineB = new PolylineBuilderEx(polylineWithoutAttrs);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will not have attributes because it is specified as a parameter
PolygonBuilderEx polygonB = new PolygonBuilderEx(points, AttributeFlags.None);
hasZ = polygonB.HasZ;                       // hasZ = false
hasM = polygonB.HasM;                       // hasM = false
hasID = polygonB.HasID;                     // hasID = false

// will have attributes because it is passed an attributed polygon
polygonB = new PolygonBuilderEx(polygonWithAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

// will not have attributes because it is passed a non-attributed polygon
polygonB = new PolygonBuilderEx(polygonWithoutAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

// Use a builderEx convenience method or a builderEx constructor.
// neither need to run on the MCT

MapPoint startPt = MapPointBuilderEx.CreateMapPoint(1.0, 1.0);
MapPoint endPt = MapPointBuilderEx.CreateMapPoint(2.0, 1.0);

List<MapPoint> list = new List<MapPoint>() { startPt, endPt };

Polyline polyline = PolylineBuilderEx.CreatePolyline(list, SpatialReferences.WGS84);

// use AttributeFlags.None since we only have 2D points in the list
PolylineBuilderEx pb = new PolylineBuilderEx(list, AttributeFlags.None);
pb.SpatialReference = SpatialReferences.WGS84;
Polyline polyline2 = pb.ToGeometry();

// Use AttributeFlags.NoAttributes because we only have 2d points in the list
Polyline polyline4 = PolylineBuilderEx.CreatePolyline(list, AttributeFlags.None);

List<MapPoint> firstPoints = new List<MapPoint>();
firstPoints.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0));
firstPoints.Add(MapPointBuilderEx.CreateMapPoint(1.0, 2.0));
firstPoints.Add(MapPointBuilderEx.CreateMapPoint(2.0, 2.0));
firstPoints.Add(MapPointBuilderEx.CreateMapPoint(2.0, 1.0));

List<MapPoint> nextPoints = new List<MapPoint>();
nextPoints.Add(MapPointBuilderEx.CreateMapPoint(11.0, 1.0));
nextPoints.Add(MapPointBuilderEx.CreateMapPoint(11.0, 2.0));
nextPoints.Add(MapPointBuilderEx.CreateMapPoint(12.0, 2.0));
nextPoints.Add(MapPointBuilderEx.CreateMapPoint(12.0, 1.0));

// use AttributeFlags.None since we have 2D points in the list
PolylineBuilderEx pBuilder = new PolylineBuilderEx(firstPoints, AttributeFlags.None);
pBuilder.AddPart(nextPoints);

Polyline polyline = pBuilder.ToGeometry();
// polyline has 2 parts

pBuilder.RemovePart(0);
polyline = pBuilder.ToGeometry();
// polyline has 1 part