Error in page: Micro DC Motor with Encoder-SJ02 SKU: FIT0458

page: https://www.dfrobot.com/wiki/index.php/Micro_DC_Motor_with_Encoder-SJ02_SKU:_FIT0458
in the arduino code example: Encoder Sample Code 1
the line: duration = 0 is inside loop() function, better inside setup() function.
in the arduino code example: Encoder Sample Code 1
the line: duration = 0 is inside loop() function, better inside setup() function.