docs: function generateIndex(base, files) {
    var document = base.copy();
    var head = document.find().only().elem('head').toValue();
  
    // set title
    head.find()
        .only().elem('title').toValue()
        .setContent('Mocha Tests - all');
  
    // bind testcases
    Object.keys(files).forEach(function (relative) {
      head.append('<script src="/test' + relative + '"></script>');
    });
  
    return document.content;
  }