actually their are at least 5 sensor when you walk across the
gate.
all sensor need to clear in sequence before the gate will close
or after expired time.
if the person in front is within your hand reach, stop any one
of the sensor with your tumb, while the person in front is walking,
the gate will remain open, even the person has completed walk
across, with your tumb blocking any one sensor,
safety feature become our free ride lop hole