public function to($system)
    {
        $this->value = $this->lookup($system);
        $this->system = $system;
        return $this;
    }
public function to($system)
    {
        $this->value = $this->lookup($system);
        $this->system = $system;
        return $this;
    }
public function to ( $ system ) { $ this -> value = $ this -> lookup ( $ system ) ; $ this -> system = $ system ; return $ this ; }
Converts this size to another system.
@param string $system system to convert to
@return Size this size
Converts this size to another system .