code: @Override
      public Object appendEL(Object o) {
  
  	if (offset + size + 1 > arr.length) enlargeCapacity(size + 1);
  	arr[offset + size] = o;
  	size++;
  	return o;
      }
docs: append a new value to the end of the array
  
  @param o value to insert
  @return inserted value