Complete the following file in Java:

/** A simulated lock with digit buttons. */ public class Lock { private int combination = 1729; private int input;

/** Simulates a digit button push. @param button a digit 0 ... 9 */ public void push(int button) { . . . } /** Simulates a push of the open button. @return true if the lock opened */ public boolean open() { . . . } }

As the data representation, use an integer containing the digits that have been entered up to this point. You will need to figure out how to update that number. For example, if the user had previously pushed 1 and 7, causing input to be 17, and now pushes 9, how can you set input to 179?

In the open method, return true if the lock would have been opened, false otherwise. Clicking that button resets the entered keys, whether or not the correct combination had been entered.