title: getting a blob from the stream
body: <p>This Meteor server code tries to create a pdf in order to attach it to an email. It  make the pdf Ok but when puting it into a blob, it returns this error: </p>
  
  <blockquote>
    <p>TypeError: Blob is not a function</p>
  </blockquote>
  
  <pre><code>"use strict";
  let PDFDocument = require('pdfkit');
  let blobStream = require('blob-stream');
  
  'make': function () {
      let doc = new PDFDocument(metaData);  // readable Node streams
      let stream = doc.pipe(blobStream());
      doc.fontSize('14')
        .text('some text')
        .end();
      stream.on('finish', function (blob) {
        return stream.toBlob(blob); //&lt;=== error line
      });
    },
  </code></pre>