/**
 * A super-simplified version the Java List interface.
 * For the actual interface's source code, see
 * 
 * https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/List.java
 */
public interface List {
  /**
   * Returns the element at the specified index.
   * @param index the position from which to return an element.
   */
  E get(int index);

  /**
   * Appends the specified element to the end of the list.
   * @param e element to be appended to this list.
   */
  void add(E e);


  /**
   * Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any)
   * and any subsequent elements to the right.
   * 
   * @param index index at which the specified element is to be inserted.
   * @param e element to be inserted.
   */
  void add(int index, E e);

  /**
   * Removes the first occurrence of the specified element from this list.
   * 
   * @param e The element to be removed from this list, if present.
   * @return {@code true} if this list contained the specified element.
   */
  boolean remove(E e);

  /**
   * Removes the element at the specified position in this list.
   * Shifts any subsequent elements to the left.
   * 
   * @param index the index of the element to be removed.
   * @return the element at the previously specified position.
   */
  E remove(int index);

  /**
   * Returns {@code true} if this list contains the specified element.
   * 
   * @param e element whose presence in this list is to be tested.
   * @return {@code true} if this list contains the specified element.
   */
  boolean contains(E e);

  /**
   * Returns the number of elements in this list. 
   * @return the number of elements in this list.
   */
  int size();
}