/**
  * Adds a new segment. It automatically sets the SQL segment depending on the column name in case none is set
  * already.
  * @see \Piwik\Columns\Dimension::addSegment()
  * @param Segment $segment
  * @api
  */
 protected function addSegment(Segment $segment)
 {
     $sqlSegment = $segment->getSqlSegment();
     if (!empty($this->columnName) && empty($sqlSegment)) {
         $segment->setSqlSegment($this->tableName . '.' . $this->columnName);
     }
     parent::addSegment($segment);
 }