How do I use this library?

Did you find any differences specific to the control protocol?

As for how to write a library. You could compare the datasheet for the VAF1613 to the library's code. It's pretty easy to follow the code, it's just using digitalWrite() and delayMicroseconds() to send pulses on the control pins in accordance with the protocol specified in the datasheet. The delays just need to fall within the specified range.