Sample code for using adafruit servo shield?
Adafruit's guide for the shield is here:
https://learn.adafruit.com/adafruit-16-channel-pwm-slash-servo-shield/using-the-adafruit-library

I'm not sure how much the library you linked and the official one differ. They seem to be used the same way, but you should probably stick with the official one.

You are going to have to use setPWM(pin, on, off) since the arduino is not generating the signals like it would with servo.write(), the arduino is sending commands to a chip on the shield that generates the signals for you.

Adafruit recommends calibrating SERVOMIN and SERVOMAX yourself with whatever brand of servo you plan on using, but those default values should be pretty close.