public function queryGroupBy($byColumn, bool $removeColumn = false): Map
	{
		return $this->source->queryGroupBy($byColumn, $removeColumn);
	}
public function queryGroupBy($byColumn, bool $removeColumn = false): Map
	{
		return $this->source->queryGroupBy($byColumn, $removeColumn);
	}
Return array where each value is an array of rows grouped by a single column.
@param string|int $byColumn Column to group by.
@param bool $removeColumn If set to true, the group by column is removed from the row.
@return Map