title: How to tell if a promise is resolved?
body: <p>Suppose some code does</p>
  
  <pre><code>// promise.js
  let p = new Promise(() =&gt; { /* ... */ })
  export default p
  </code></pre>
  
  <p>where <code>Promise</code> is an ES6 Promise. Suppose some other code has a reference only to <code>p</code>. How can that code tell if <code>p</code> is resolved or not?</p>
  
  <pre><code>// other.js
  import p from './promise.js'
  // console.log('p is resolved?', ______)
  </code></pre>
  
  <p>Is there something we can fill in the blank with that would show true or false depending on whether the promise is resolved or not?</p>