code: public function mergeRow(array $arrData)
  	{
  		foreach ($arrData as $k=>$v)
  		{
  			if (strpos($k, '__') !== false)
  			{
  				continue;
  			}
  
  			if (!isset($this->arrModified[$k]))
  			{
  				$this->arrData[$k] = $v;
  			}
  		}
  
  		return $this;
  	}
docs: Set the current record from an array preserving modified but unsaved fields
  
  @param array $arrData The data record
  
  @return static The model object