code: function BlobReadStream(blob, options) {
    if (!(this instanceof BlobReadStream)) {
      return new BlobReadStream(blob, options);
    }
  
    Readable.call(this, options);
  
    options = options || {};
    this.blob = blob;
    this.slice = blob.slice || blob.webkitSlice || blob.mozSlice;
    this.start = 0;
    this.sync = options.synchronous || false;
  
    var fileReader;
  
    if (options.synchronous) {
      fileReader = this.fileReader = new FileReaderSync();
    } else {
      fileReader = this.fileReader = new FileReader();
    }
  
    fileReader.onload = bind(this, '_onload');
    fileReader.onerror = bind(this, '_onerror');
  }
docs: Readable stream for Blob and File on browser.
  
  @param {Object} options
  @api private