public function setIndexByName($sheetName, $newIndex)
    {
        $oldIndex = $this->getIndex($this->getSheetByName($sheetName));
        $pSheet = array_splice(
            $this->workSheetCollection,
            $oldIndex,
            1
        );
        array_splice(
            $this->workSheetCollection,
            $newIndex,
            0,
            $pSheet
        );
        return $newIndex;
    }