$4.$ Double$-$click Wallet.java to open the code for the Wallet class then examine this code. Familiarize yourself with both the tickets array and the size variable and understand how they are used$\mathrm{.}5.$ There is no method for removing a ConcertTicket from a Wallet. Your job is to write a method named remove. It should take no parameters and return the ConcertTicket object that was removed. Here is some basic pseudocode for this method: public ConcertTicket remove$()\{//$ Create a ConcertTicket reference variable.$//$ DO NOT create an object, only the reference variable.$//$ Use the size variable to access the last added ConcertTicket and$//$ point the reference variable to this object.$//$ Set that array element to null$//$ Decrement the size variable$//$ return the ConcertTicket $\}6.$ Write this method then save the changes you made before moving on$.$Write a Test Case