public interface MyList<E> {

  // appends elem to the end
  public void add( E elem );

  // inserts elem at index  
  // shifts the current and any subsequent elements down
  public void add( int index, E elem );

  // replaces the element at index with elem
  // returns the element previously at index
  public E set( int index, E elem );

  // returns the element at index
  public E get( int index );

  // removes first occurrence of elem if found, 
  // shift subsequent elemenets up, and return true,
  // else return false and no changes are made
  public boolean remove( E elem );

  // removes the element at index and shifts subsequent elements up
  // returns the element that was removed
  public E       remove( int index );

  // removes all of the elements from this list
  public void    clear();

  // returns the index of the first occurrence of elem
  // or -1 if elem not found
  public int indexOf( E elem );

  // returns the index of the last occurrence of elem
  // or -1 if elem not found
  public int lastIndexOf( E elem );

  // returns true if this list contains elem, false otherwise
  public boolean contains( E elem );

  // returns true if list has no elements, false otherwise
  public boolean isEmpty();

  // returns the number of elements in list
  // returns Integer.MAX_VALUE, if size > Integer.MAX_VALUE elements
  public int size();
}