install gulp to process code

node_modules/undertaker/lib/tree.js

@@ -0,0 +1,25 @@
+'use strict';
+
+var metadata = require('./helpers/metadata');
+
+function tree(opts) {
+  opts = Object.assign({ deep: false }, opts);
+
+  var tasks = this._registry.tasks();
+  var nodes = Object.values(tasks).map(function(task) {
+    var meta = metadata.get(task);
+
+    if (opts.deep) {
+      return meta.tree;
+    }
+
+    return meta.tree.label;
+  });
+
+  return {
+    label: 'Tasks',
+    nodes: nodes,
+  };
+}
+
+module.exports = tree;