public class Bag extends List

public class Bag{
	private List bag;
	
	public T remove(){
		bag.remove(0);
	}
}


public class List {
	T[] list;
	int numEntries;
	
	public T getEntry(int position) {
		return list[position-1];
	}
	
	public void add(int newPosition, T newValue) {
		newPosition = newPosition - 1;
		
		//make sure there's room in the array
		if (numEntries == list.length)
		{
			doubleCapacity();
		}
		
		makeRoom(newPosition);
		list[newPosition] = newValue;
		numEntries++;
	}
	
	public T remove (int givenPosition)
	{
		if (numEntries == 0) throw new IndexOutOfBoundsException("...");
		if (givenPosition > numEntries) throw new IndexOutOfBoundsException("...");
		if (givenPosition <= 0)  throw new IndexOutOfBoundsException("...");
		
		givenPosition--;
		
		T removedValue = list[givenPosition];
		removeGap(givenPosition);
		
		numEntries--;
		return removedValue;
	}
	
	private void removeGap(int position) {
		//assert to ensure position is valid
		for (int i = position; i < numEntries-1; i++) {
			list[i] = list[i+1];
		}
		return;
	}
	
	private void makeRoom(int newPosition) {     //ensure newPosition is a valid location for makeRoom:
		assert (newPosition >= 1) && (newPosition <= numberOfEntries+1);
		
		// move each entry to next higher index, starting at end of
		// list and continuing until the entry at newPosition is moved
		int newIndex = newPosition;
		int lastIndex = numberOfEntries;
		for (int index = lastIndex; index >= newIndex; index--)
		{
			list[index+1] = list[index];
		}
	} 
}
list.getEntry(2);
list.add(2, "cat");
list.remove(2);