Piwik\DataTable::setLabelsHaveChanged PHP Method

    public function setLabelsHaveChanged()
    {
        $this->indexNotUpToDate = true;
    }

 /**
  * See {@link GroupBy}.
  *
  * @param DataTable $table
  */
 public function filter($table)
 {
     /** @var Row[] $groupByRows */
     $groupByRows = array();
     $nonGroupByRowIds = array();
     foreach ($table->getRowsWithoutSummaryRow() as $rowId => $row) {
         $groupByColumnValue = $row->getColumn($this->groupByColumn);
         $groupByValue = $groupByColumnValue;
         // reduce the group by column of this row
         if ($this->reduceFunction) {
             $parameters = array_merge(array($groupByColumnValue), $this->parameters);
             $groupByValue = call_user_func_array($this->reduceFunction, $parameters);
         }
         if (!isset($groupByRows[$groupByValue])) {
             // if we haven't encountered this group by value before, we mark this row as a
             // row to keep, and change the group by column to the reduced value.
             $groupByRows[$groupByValue] = $row;
             $row->setColumn($this->groupByColumn, $groupByValue);
         } else {
             // if we have already encountered this group by value, we add this row to the
             // row that will be kept, and mark this one for deletion
             $groupByRows[$groupByValue]->sumRow($row, $copyMeta = true, $table->getMetadata(DataTable::COLUMN_AGGREGATION_OPS_METADATA_NAME));
             $nonGroupByRowIds[] = $rowId;
         }
     }
     if ($this->groupByColumn === 'label') {
         $table->setLabelsHaveChanged();
     }
     // delete the unneeded rows.
     $table->deleteRows($nonGroupByRowIds);
 }