public function getColumnContent($record, $column)
    {
        if (!$this->columnDispatch) {
            $this->buildColumnDispatch();
        }

        if (!empty($this->columnDispatch[$column])) {
            $content = '';

            foreach ($this->columnDispatch[$column] as $handler) {
                /**
                 * @var GridField_ColumnProvider $handler
                 */
                $content .= $handler->getColumnContent($this, $record, $column);
            }

            return $content;
        } else {
            throw new InvalidArgumentException(sprintf(
                'Bad column "%s"',
                $column
            ));
        }
    }