/**
 * A librarian wants to find the books that are common between two users' book sets.
 *
 * @param user1Books A set containing the books of user1.
 * @param user2Books A set containing the books of user2.
 * @return The set containing the books that are common between user1Books and user2Books.
 */
fun findBooksInIntersection(user1Books: Set<String>, user2Books: Set<String>): Set<String> {

    val intersection = user1Books.intersect(user2Books)  // Finding the intersection using the intersect function
    return intersection
}

// Example usage:
/**
 * A librarian wants to find the books that are common between two users' book sets.
 *
 * @param user1Books A set containing the books of user1.
 * @param user2Books A set containing the books of user2.
 * @return The set containing the books that are common between user1Books and user2Books.
 */
fun findBooksInIntersection(user1Books: Set<String>, user2Books: Set<String>): Set<String> {
/**
 * A librarian wants to find the books that are common between two users' book sets.
 *
 * @param user1Books A set containing the books of user1.
 * @param user2Books A set containing the books of user2.
 * @return The set containing the books that are common between user1Books and user2Books.
 */
fun findBooksInIntersection(user1Books: Set<String>, user2Books: Set<String>): Set<String> {

    val intersection = user1Books.intersect(user2Books)  // Finding the intersection using the intersect function
    return intersection
}

// Example usage: