The PDFBox2.0 trans to image,but the "org.apache.pdfbox.tools.imageio" cann't find

On the apache PDFBox web sit,http://pdfbox.apache.org/2.0/migration.html ,the PDF Rendering example.

ImageIOUtil.writeImage(bim, pdfFilename + "-" + (pageCounter++) + ".png", 300);

the ImageIOUtil cann't find.help me,Thanks