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final class BankAccount implements Comparable<BankAccount> {
  private double balanceAmount;  // Total amount in bank account	 
  private final Object lock;

  private final long id; // Unique for each BankAccount
  private static long nextID = 0; // Next unused id

  private BankAccount(double balance) {
    this.balanceAmount = balance;
    this.lock = new Object();
    this.id = this.nextID++;
  }

  public int compareTo(BankAccount ba) {
    if (this.id < ba.id) {
      return -1;
    }// No need to check for overflow because the type long is large
    if (this.id > ba.id) {
      return 1;// enough to hold the required number of bank accounts
    }
    return 0;return (this.id - ba.id); 
  }

  // Deposits the amount from this object instance to BankAccount instance argument ba 
  public void depositAmount(BankAccount ba, double amount) {
    BankAccount former, latter;
    if (compareTo(ba) < 0) {
      former = this;
      latter = ba;
    } else {
      former = ba;
      latter = this;
    }
    synchronized (former) {
      synchronized (latter) {
        if (amount > balanceAmount) {
          throw new IllegalArgumentException("Transfer cannot be completed");
        }
        ba.balanceAmount += amount;
        this.balanceAmount -= amount; 
      } 
    }
  }
 
  public static void initiateTransfer(final BankAccount first,
    final BankAccount second, final double amount) {
   
    Thread t = new Thread(new Runnable() {
      public void run() {
        first.depositAmount(second, amount);
      }
    });
    t.start();
  }
}