Of course not. Now there is all the fun of testing the implementation.
Here is an expanded test program for the class. The class itself is given in the previous page, so if you are going to run this program (could there be any doubt?) you will have to copy and paste two things into your text editor.
class CheckingAccount { . . . . } class CheckingAccountTester { public static void main( String[] args ) { CheckingAccount account1 = new CheckingAccount( "123", "Bob", 100 ); System.out.println( account1.currentBalance() ); account1.processDeposit( 2000 ); account1.processCheck( 1500 ); System.out.println( account1.currentBalance() ); } }