code: @Override
  	public int set(int index, int element) {
  		RangeCheck(index);
  
  		int oldValue = elementData[index];
  		elementData[index] = element;
  		return oldValue;
  	}
docs: Replaces the element at the specified position in this list with
  the specified element.
  
  @param index index of element to replace.
  @param element element to be stored at the specified position.
  @return the element previously at the specified position.
  @throws    IndexOutOfBoundsException if index out of range
  <tt>(index &lt; 0 || index &gt;= size())</tt>.