XBee transparent mode with Alternate pins.

I am looking through:

and I don't see a whole lot in the way of setup structure for global variables.

I did see (Loop) [loop() - Arduino Reference]:

int buttonPin = 3;

// setup initializes serial and the button pin
void setup()
{
  beginSerial(9600);
  pinMode(buttonPin, INPUT);
}

// loop checks the button pin each time,
// and will send serial if it is pressed
void loop()
{
  if (digitalRead(buttonPin) == HIGH)
    serialWrite('H');
  else
    serialWrite('L');

  delay(1000);
}

When it calls the serial, it uses:

beginSerial(9600);

Instead of:

Serial.begin(9600)

So how does that work?

And I couldn't go from:

WirelessSerial.begin(9600);

To:

beginwirelessserial(9600);

or something similar could I? Is this sort of on track with what you were explaining to me?

I usually know what I want the code to do, but getting it into the correct context, now there's the trick... Is there some other place that references different "setups"?

Thanks,
Ec7