code: public MultiChangeBuilder<PS, SEG, S> insertAbsolutely(int paragraphIndex, int columnPosition, StyledDocument<PS, SEG, S> document) {
          int pos = area.getAbsolutePosition(paragraphIndex, columnPosition);
          return replaceAbsolutely(pos, pos, document);
      }
docs: Inserts the given rich-text content at the position returned from
  {@code getAbsolutePosition(paragraphIndex, columnPosition)}.
  
  <p><b>Caution:</b> see {@link StyledDocument#getAbsolutePosition(int, int)} to know how the column index argument
  can affect the returned position.</p>
  
  @param document The rich-text content to insert.