public function setUpdatedOn($updated_on) {
        
        $this -> updated_on = $updated_on !== null ? new \DateTime($updated_on) : null;
        return $this;
    }
public function setUpdatedOn($updated_on) {
        
        $this -> updated_on = $updated_on !== null ? new \DateTime($updated_on) : null;
        return $this;
    }
public function setUpdatedOn ( $ updated_on ) { $ this -> updated_on = $ updated_on !== null ? new \ DateTime ( $ updated_on ) : null ; return $ this ; }
Sets the updated on
@param string $updated_on
@return TimestampAwareTrait
Sets the updated on