import java.util.NoSuchElementException;

public interface LinkedListInterface {
    /**
     * The number of items in the linked list
     * 
     * @return the number of items in the linked list
     */
    int size();

    /**
     * Returns true iff the linked list has no elements
     * 
     * @return true iff the linked list has no elements
     */
    boolean isEmpty();

    /**
     * Get the first element in the linked list
     * 
     * @return the first element in the linked list
     * @throws NoSuchElementException is the list is empty
     */
    Rabbit first() throws NoSuchElementException;

    /**
     * The last element in the linked list
     * 
     * @return the last elment
     * @throws NoSuchElementException if the linked list is empty
     */
    Rabbit last() throws NoSuchElementException;

    /**
     * Add a rabbit at the end of the list
     * 
     * @param c the rabbit to be added
     */
    void addLast(Rabbit c);

    /**
     * Add a rabbit at the front of the list
     * 
     * @param c the rabbit to be added
     */
    void addFirst(Rabbit c);

    /**
     * Remove the first rabbit from the list
     * 
     * @return the first rabbit, or null if the list is empty
     */
    Rabbit removeFirst();

    /**
     * Remove the last rabbit from the list
     * 
     * @return the last rabbit, or null if the list is empty
     */
    Rabbit removeLast();

    /**
     * Remove the specified rabbit from the list
     * 
     * @param r the rabbit to be removed
     * @return the removed rabbit, or null is the rabbit was not in the list
     */
    Rabbit remove(Rabbit r);

    /**
     * Find a rabbit in the list by its iD
     * 
     * @param iD
     * @return the found rabbit, or null if a match could not be found
     */
    Rabbit find(String iD);
}