function createHook(handler) {
    return function nodeDevHook(module, filename) {
      if (!module.loaded) callback(module.filename);

      // Invoke the original handler
      handler(module, filename);

      // Make sure the module did not hijack the handler
      updateHooks();
    };
  }
Returns a function that can be put into `require.extensions` in order to
invoke the callback when a module is required for the first time.