public function getOldTable(): TableStructure
    {
        if ($this->_oldTable === null) {
            $this->_oldTable = new TableStructure([
                'schema' => get_class($this->db->schema),
                'generalSchema' => $this->generalSchema,
                'usePrefix' => $this->useTablePrefix,
                'dbPrefix' => $this->db->tablePrefix,
            ]);

            $this->_oldTable->applyChanges(array_reverse($this->_appliedChanges));
        }

        return $this->_oldTable;
    }