private function AddConstants($columnsMetadata) {
        $output = "";
        foreach ($columnsMetadata as $columnName => $columnMetadata) {
            $output .= $this->_TAB2 . "const " . strtoupper($columnMetadata["Field"]) . " = \"" . $columnMetadata["Field"] . "\";" . $this->_LF;
        }
        $output .= $this->_CRLF;
        fwrite($this->writer, $output);
    }