classDiagram
    class Borrower {
        -items ArrayList~Publication~

        +borrow(item: Publication)
        +getItems() ArrayList~Publication~


    }

    class Student {
        - studentId

        +getId() String
    }

    Student --|> Borrower

    class Publication {

    }

    class Book {

    }

    Book --|> Publication

    Borrower --> Publication: borrows