7.1 Use the SinglyLinkedList class three times. First, create a SinglyLinkedList object, team1, with elements of type String. Add three elements to team1 Second, create team2, another SinglyLinkedList object with elements of type String. Add four elements to team2. Finally, create a SinglyLinkedList object, league, whose elements are SinglyLinkedList objects of teams. Add team1 and team2 to league