How to check ready() of package in client template?

I use package, and I want to check ready() in my template

   return data;
   return 'Loading...';

There is no ready test, it returns undefined when first run, followed by the actual call result when successful:

So, you should be able to do:

var result ='myMethod');
if ('undefined' === typeof result) {
  return 'Loading...';
} else {
  return result;