public function getColumns()
{
$result = array();
foreach ($this->getRows() as $row) {
$columns = $row->getColumns();
if (!empty($columns)) {
$result = array_keys($columns);
break;
}
}
// make sure column names are not DB index values
foreach ($result as &$column) {
if (isset(Metrics::$mappingFromIdToName[$column])) {
$column = Metrics::$mappingFromIdToName[$column];
}
}
return $result;
}