A network device and method are directed towards detecting and blocking image spam within a message by employing a weighted min-hash to perform a near duplicate detection of determined features within an image as compared to known spam images. Operation of the motor results in the motoring propeller to rotate and generate an accelerating slipstream towards the generating propeller which results in the generator rotating to convert recovered rotational energy into other forms of useable energy. The rest of the content stream is sent in the clear. The characterization procedure may be carried out at a test bench or with the toner patch sensor installed in the corresponding device. This new cultivar has white bark and dark green leaves in addition to being highly resistant to bronze birch borer.