text: const fs = require('fs');
  
  const angularPackageJsonFile = fs.readFileSync('./node_modules/@angular/core/package.json');
  const angularPackageJson = JSON.parse(angularPackageJsonFile);
  const angular = angularPackageJson['version'];
  
  const ng2PdfViewerJsonFile = fs.readFileSync('./node_modules/ng2-pdf-viewer/package.json');
  const ng2PdfViewerJson = JSON.parse(ng2PdfViewerJsonFile);
  const ng2PdfViewer = ng2PdfViewerJson['version'];
  
  const extendedPdfViewerJsonFile = fs.readFileSync('./node_modules/ngx-extended-pdf-viewer/package.json');
  const extendedPdfViewerJson = JSON.parse(extendedPdfViewerJsonFile);
  const extendedPdfViewer = extendedPdfViewerJson['version'];
  
  const pdfJsDistJsonFile = fs.readFileSync('./node_modules/pdfjs-dist/package.json');
  const pdfJsDistJson = JSON.parse(pdfJsDistJsonFile);
  const pdfJsDist = pdfJsDistJson['version'];
  
  const version =`export const versions = {
    angular: '${angular}',
    extendedPdfViewer: '${extendedPdfViewer}',
    ng2PdfViewer: '${ng2PdfViewer}',
    pdfJsDist: '${pdfJsDist}'
  } `;
  
  fs.writeFileSync("./src/app/nav/versions.ts", version);
  