title: How to define Object of Objects type in typescript
body: <p>I have an object to store cached data which should look like this:</p>
  
  <pre><code>private data = {
     'some_thing': new DataModel(),
     'another_name': new DataModel()
  }
  </code></pre>
  
  <p>I'm trying to assign an empty object to it in the constructor:</p>
  
  <pre><code>this.data = {}; // produces build error
  </code></pre>
  
  <p>Basically, i need to define the type of "data" field to say that it's going to have keys with random names and values of type DataModel. I've tried to do this:</p>
  
  <pre><code>private data: Object&lt;DataModel&gt;
  </code></pre>
  
  <p>But this is invalid. How would i specify a correct type?</p>