The file of BankAccountTester.java

/**
   A class to test the BankAccount class.
*/
public class BankAccountTester
{
   /**
      Tests the methods of the BankAccount class.
      @param args not used
   */
   public static void main(String[] args)
   {
      BankAccount harrysChecking = new BankAccount();
      harrysChecking.deposit(2000);
      harrysChecking.withdraw(500);
      System.out.println(harrysChecking.getBalance());
      System.out.println("Expected: 1500");      
   }
}

The steps to run the program:

1. Store BankAccount.java and BankAccountTester.java in a folder.
2. Compile eaach java file.
3. run BankAccountTester

Output:
1500.0
Expected: 1500