// Aforementioned method to return available animals.
    public int getAvailableAnimals() {
        return totalAnimals - loanedAnimals;
    }

    // Checks if the number of available animals is greater than 1, or an exception is thrown as its impossible to return
    // an animal if none are available.
    public void loanAnimal() {

        if (getAvailableAnimals() < 1) {
            throw new IllegalStateException("No Animals Available to Loan.");
        }

        loanedAnimals++;
    }


    // Checks if the number of loaned animals is greater than 1, or an exception is thrown as its impossible to return
    // an animal if none are on loan.
    public void returnAnimal() {

        if (this.loanedAnimals < 1) {
            throw new IllegalStateException("No Animals are on Loan.");
        }

        loanedAnimals--;
    }
}