code: public void setLineBox(LineBox linebox)
      {
          this.linebox = linebox;
          for (int i = startChild; i < endChild; i++)
          {
              Box sub = getSubBox(i);
              if (sub instanceof InlineElement)
                  ((InlineElement) sub).setLineBox(linebox);
          }
      }
docs: Assigns the line box assigned to this inline box and all the inline sub-boxes.
  @param linebox The assigned linebox.