frequency 1000Hz is becoming 20Hz in library

[maxxlife]

DFRobot_RaspberryPi_Motor/python/raspberryPi/DFRobot_RaspberryPi_DC_Motor.py

Line 162 in 28c6fb7

frequency = int(frequency / 50)

Why you say that frequency is 1000Hz, if in the library you divide value 1000 by 50? Then value "frequency" becomes 20.