public function withModified($time)
    {
        $date = $this->_getUTCDate($time);

        return $this->withHeader('Last-Modified', $date->format('D, j M Y H:i:s') . ' GMT');
    }
public function withModified($time)
    {
        $date = $this->_getUTCDate($time);

        return $this->withHeader('Last-Modified', $date->format('D, j M Y H:i:s') . ' GMT');
    }
public function withModified ( $ time ) { $ date = $ this -> _getUTCDate ( $ time ) ; return $ this -> withHeader ( 'Last-Modified' , $ date -> format ( 'D, j M Y H:i:s' ) . ' GMT' ) ; }
Create a new instance with the Last-Modified header set.

### Examples:

```
// Will Expire the response cache now
$response->withModified('now')

// Will set the expiration in next 24 hours
$response->withModified(new DateTime('+1 day'))
```

@param string|\DateTimeInterface $time Valid time string or \DateTimeInterface instance.
@return static
Create a new instance with the Last - Modified header set .