public function addColumn($data)
    {
        if ($data instanceof Column) {
            $column = $data;
            $this->indexColumns[] = $column->getName();
            if ($column->getSize()) {
                $this->indexColumnSizes[$column->getName()] = $column->getSize();
            }
        } else {
            $attrib = $data;
            $name = $attrib["name"];
            $this->indexColumns[] = $name;
            if (isset($attrib["size"])) {
                $this->indexColumnSizes[$name] = $attrib["size"];
            }
        }
    }