code: void setAction(PdfAction action, float llx, float lly, float urx, float ury) {
          addAnnotation(new PdfAnnotation(writer, llx, lly, urx, ury, action));
      }
docs: Implements an action in an area.
  @param action the <CODE>PdfAction</CODE>
  @param llx the lower left x corner of the activation area
  @param lly the lower left y corner of the activation area
  @param urx the upper right x corner of the activation area
  @param ury the upper right y corner of the activation area