code: public T defaultPriority(Double priority) {
  		if (priority < 0.0 || priority > 1.0) {
  			throw new InvalidPriorityException("Priority must be between 0 and 1.0");
  		}
  		defaultPriority = priority;
  		return getThis();
  	}
docs: Sets default priority for all subsequent WebPages
  @param priority Default priority
  @return this