code: public Account getChild(int index) throws IndexOutOfBoundsException {
          if (index < 0 || index >= children.size())
              throw new IndexOutOfBoundsException("Illegal child index, " + index);
          return children.get(index);
      }
docs: Gets a specifically indexed child.
  
  @param index The index of the child to get.
  @return The child at the index.
  @throws IndexOutOfBoundsException upon invalid index.