code: function createFile(tree, name, prop, options) {
      var opts = utils.extend({}, options);
      var str = create(tree[name], {label: 'cwd'});
      var file = new utils.File({path: `${prop}-${name}.txt`, contents: new Buffer(str)});
  
      if (typeof opts.treename === 'function') {
        opts.treename(file);
      }
      file.writeFile = true;
      file.render = false;
      file.layout = null;
      file.isTree = true;
      utils.contents.sync(file);
      return file;
    }
docs: Create a file