public function setCellValue($columnId, $rowId, $content, $forceCreation = false)
    {
        $returnValue = (bool) false;

        
		//TODO: for creating row and column if not exists?
		if(isset($this->columns[$columnId])){
			if(isset($this->rows[$rowId])){
				$this->rows[$rowId][$columnId] = $content;
				$returnValue = true;
			}
		}
        

        return (bool) $returnValue;
    }