code: public TextBuilder styledSpan(final String text, final TextStyle ts) {
          this.curParagraphBuilder.styledSpan(text, ts);
          return this;
      }
docs: Adds a TextStyle and text to the footer/header region specified by
  region.<br>
  The paragraph to be used is paragraph.<br>
  The text will be shown in the order it was added with this function.
  
  @param text The string with the text
  @param ts   The text style to be used
  @return this for fluent style