public boolean equals(Object f) {
	if(!f.instanceof(FIFO)) {
		throw new ClassCastException("Wrong class type");
	}

	if(this.size() != f.size())
		return false;

	for(int i=0; i<f.size(); i++) {
		if(this.get(i) == null && f.get(i) != null)
			return false;
		if(!this.get(i).equals(f.get(i)))
			return false;
	}

	return true;
}