code: function utility(name, o) {
    const {root} = o.scope;
  
    if (root.utilities[name]) {
      return root.utilities[name];
    }
  
    const ref = root.freeVariable(name);
    root.assign(ref, UTILITIES[name](o));
    root.utilities[name] = ref;
  }
docs: Helper for ensuring that utility functions are assigned at the top level. copied from coffee-script compiler