public boolean equals(Object o) {
public synchronized boolean equals(Object o) {
    public boolean equals(Object o) {        if (o instanceof BankAccount) {            BankAccount test = (BankAccount)o;            return this.transactions.equals(test.transactions);            //No need to look at the current balance field since it             //can be calculated by looking at the transactions.        } else {            return false;        }    }