private void ButtonSetSample_Click(object sender, EventArgs e)
 {
     try
     {
         _instance.AddSymbol(_symbol.GetXrepresentors(), _symbol.GetYrepresentros(), _whichClass, _params.Symbols);
         UiHandler.DecrementValue(tableClasses, _whichClass);
     }
     catch (Exception)
     {
         // ignored
     }
     buttonSetSample.Enabled = false;
     _drawer.ResetPoints();
     if (UiHandler.AllButtonsDisabled(tableClasses))
     {
         SaveTestSet.Enabled = true;
     }
 }