public void SelectSolutionBySol(CasePalletSolution sol)
        {
            if (HasSolutionSelected(sol))
            {
                return;
            }
            // instantiate new SelSolution
            SelCasePalletSolution selSolution = new SelCasePalletSolution(ParentDocument, this, sol);

            // insert in list
            _selectedSolutions.Add(selSolution);
            // fire event
            if (null != SolutionSelected)
            {
                SolutionSelected(this, selSolution);
            }
            // set document modified (not analysis, otherwise selected solutions are erased)
            ParentDocument.Modify();
        }