docs: public static int getPdfPageCount(File inputPdfFile) {
          if (PDFBOX.equals(System.getProperty(PDF_LIBRARY))) {
              return PdfBoxUtilities.getPdfPageCount(inputPdfFile);
          } else {
              try {
                  return PdfGsUtilities.getPdfPageCount(inputPdfFile);
              } catch (Exception e) {
                  System.setProperty(PDF_LIBRARY, PDFBOX);
                  return getPdfPageCount(inputPdfFile);
              }
          }
      }