Ok, so I'm trying to change this code over to

``` javascript
  busboy.on('file', function (name, file, filename, encoding, mimetype) {
    if (name === 'dexcom') {
      var bytesWritten = 0;
      var out = es.through(
        function(chunk){
          bytesWritten += chunk.length;
          this.queue(chunk);
        },
        function(){
          log.info('Loaded dexcom data, [%s] bytes', bytesWritten);
          if (bytesWritten > 0) {
            memo[name] = out;
            memo.dexcom.encoding = encoding;
            memo.dexcom.name = filename;
            memo.dexcom.type = mimetype;
          }
          this.queue(null);
        }
      ).pause();
      file.pipe(out);
    } else {
      // resume() the ignored streams, otherwise busboy won't fire the 'finish' event.
      file.resume();
    }
  });
```

And it's just hanging on dexcom uploads now.  What am I doing wrong with the through stream that the old method was handling correctly?