code: public PdfContentByte getDuplicate() {
          PdfPatternPainter tpl = new PdfPatternPainter();
          tpl.writer = writer;
          tpl.pdf = pdf;
          tpl.thisReference = thisReference;
          tpl.pageResources = pageResources;
          tpl.bBox = new Rectangle(bBox);
          tpl.xstep = xstep;
          tpl.ystep = ystep;
          tpl.matrix = matrix;
          tpl.stencil = stencil;
          tpl.defaultColor = defaultColor;
          return tpl;
      }
docs: Gets a duplicate of this <CODE>PdfPatternPainter</CODE>. All
  the members are copied by reference but the buffer stays different.
  @return a copy of this <CODE>PdfPatternPainter</CODE>