code: function createNode(src, raw, files, config) {
    var node = new FilesNode(src, raw, config);
    if (node.path || node.src) {
      files.push(node);
    }
  }
docs: Create a new `Node` and push it onto the `files` array if the
  returned node has a `path` or `src` property. In plugins, you
  may remove the `src` and/or `path` properties to prevent nodes
  from being pushed onto the array.