void BtnSortClick(object sender, EventArgs e)
        {
            SortModel sortModel = new SortModel();

            sortModel.inputText    = tbInput.Text;
            sortModel.sortStrategy = (SortStrategy)this.cmbStrategy.SelectedValue;
            List <string> errors = sortModel.validate();

            if (errors.Count > 0)
            {
                string errorMessage = "";
                foreach (string err in errors)
                {
                    errorMessage = errorMessage + err + ".";
                }
                MessageBox.Show(errorMessage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            tbOutput.Text = SortController.sortTextByStrategy(sortModel);

            MessageBox.Show("String Sorted", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
 public static string sortTextByStrategy(SortModel sortModel)
 {
     return(sortModel.sort());
 }