docs: function loadAttachments (doc, directory, callback) {
    doc._attachments = doc._attachments || {};
    glob('**/*', { cwd: directory }, function (err, files) {
      async.each(files, function (file, done) {
        if (file.indexOf('_') === 0) return done();
        fs.stat(path.join(directory, file), function (err, stat) {
          if (err) return done(err);
          if (stat.isFile()) {
            fs.readFile(path.join(directory, file), function (err, data) {
              if (err) return done(err);
              var ext = file.split('.').pop()
              doc._attachments[file] = {}
              doc._attachments[file]['content_type'] = lookup(ext);
              doc._attachments[file]['data'] = data.toString('base64');
              done();
            });
          } else {
            done();
          }
        });
      }, function (err) {
        callback.call(null, err, doc);
      });
    });
  }