code: public MultiChangeBuilder<PS, SEG, S> insertAbsolutely(int position, StyledDocument<PS, SEG, S> document) {
          return replaceAbsolutely(position, position, document);
      }
docs: Inserts the given rich-text content at the given position.
  
  @param position The position to insert the text.
  @param document The rich-text content to insert.