docs: public void beforeInsert(int index, Object element) {
  	// overridden for performance only.
  	if (index > size || index < 0) 
  		throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
  	ensureCapacity(size + 1);
  	System.arraycopy(elements, index, elements, index+1, size-index);
  	elements[index] = element;
  	size++;
  }