protected override void OnClick()
        {
            ICadastralEditor           pCadEd         = (ICadastralEditor)ArcMap.Application.FindExtensionByName("esriCadastralUI.CadastralEditorExtension");
            IParcelEditManager         pParcEditorMan = (IParcelEditManager)pCadEd;
            ICadastralExtensionManager pCadMan        = pCadEd as ICadastralExtensionManager;
            ICadastralPacketManager    pCadPacketMan  = (ICadastralPacketManager)pCadEd;

            //bool bStartedWithPacketOpen = pCadPacketMan.PacketOpen;

            if (!(pCadMan.ContextItem is IGSLine))
            {
                return;
            }

            IGSLine pGSLine = pCadMan.ContextItem as IGSLine;

            if (pParcEditorMan == null)
            {
                return;
            }

            IEditor pEd = (IEditor)ArcMap.Application.FindExtensionByName("esri object editor");

            if (pEd.EditState == esriEditState.esriStateNotEditing)
            {
                MessageBox.Show("Please start editing and try again.");
                return;
            }

            IParcelConstruction     pConstr   = pParcEditorMan.ParcelConstruction;
            ICadastralLinePoints2Ex pCadLPsEx = pConstr as ICadastralLinePoints2Ex;

            ILongArray pLngArrBefore = pCadLPsEx.LinePoints;
            List <int> lstLPBefore   = new List <int>();

            for (int i = 0; i < pLngArrBefore.Count; i++)
            {
                lstLPBefore.Add(pLngArrBefore.get_Element(i));
            }

            //first get the current set of breakpoints
            Utilities FabUTILS = new Utilities();

            FabUTILS.ExecuteCommand("{9987F18B-8CC4-4548-8C41-7DB51F289BB3}"); //Run COTS Breakline command

            ILongArray pLngArrAfter = pCadLPsEx.LinePoints;
            List <int> lstLPAfter   = new List <int>();

            for (int i = 0; i < pLngArrAfter.Count; i++)
            {
                lstLPAfter.Add(pLngArrAfter.get_Element(i));
            }

            List <int> lstNewBreakPoints = lstLPAfter.Except(lstLPBefore).ToList();

            if (lstNewBreakPoints.Count == 0)
            {
                return;
            }

            IParcelConstruction4 pConstr4      = pConstr as IParcelConstruction4;
            ICadastralPoints     pCadastralPts = pConstr4 as ICadastralPoints;

            IEnumCELines pCELines     = new EnumCELinesClass();
            IEnumGSLines pEnumGSLines = (IEnumGSLines)pCELines;

            pCELines.Add(pGSLine);

            //check if it's a construction line or parent line
            bool         bIsParentLine            = true;
            IEnumGSLines pEnumGSConstructionLines = pConstr4.GetLines(false, false);

            IGSLine   pGSTestLine = null;
            IGSParcel pGSParc     = null;

            pEnumGSConstructionLines.Reset();
            pEnumGSConstructionLines.Next(ref pGSParc, ref pGSTestLine);
            while (pGSTestLine != null)
            {
                if ((pGSLine.FromPoint == pGSTestLine.FromPoint) && (pGSLine.ToPoint == pGSTestLine.ToPoint))
                {
                    bIsParentLine = false;
                    break;
                }
                pEnumGSConstructionLines.Next(ref pGSParc, ref pGSTestLine);
            }

            IParcelLineFunctions3 pParcLineFunctions = new ParcelFunctionsClass();
            IEnumGSLines          pNewLinesEnum      = pParcLineFunctions.BreakLinesAtLinePoints(pEnumGSLines, pCadastralPts, true, false);

            IGSParcel          pGSParcel    = null;
            IGSLine            pGSNewLine   = null;
            ICadastralUndoRedo pCadUndoRedo = pConstr as ICadastralUndoRedo;

            pCadUndoRedo.StartUndoRedoSession("Break-line");

            pNewLinesEnum.Reset();
            pNewLinesEnum.Next(ref pGSParcel, ref pGSNewLine);
            while (pGSNewLine != null)
            {
                pConstr4.InsertGridRow(-1, pGSNewLine, true);
                pNewLinesEnum.Next(ref pGSParcel, ref pGSNewLine);
            }

            ICadastralUnbuildableLines pUnbuildable = pConstr4 as ICadastralUnbuildableLines;

            if (bIsParentLine)
            {
                pUnbuildable.AddLine(pGSLine);
            }
            else
            {
                pConstr4.Planarize(0.001); //delete the original construction line
            }
            pCadUndoRedo.WriteUndoRedoSession(true);
        }