<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_channel_pulse(dma_channel, gpio, start, width):
 """ Add a pulse for a specific GPIO to a dma channel subcycle. `start` and `width` are multiples of the pulse-width increment granularity. """

    return _PWM.add_channel_pulse(dma_channel, gpio, start, width)