title: Finding a key in an object that’s true AND matches en entry in an array
body: <p>I have an array like this:</p>
  
  <pre><code>baseBreakpoints: [
      'xLarge',
      'large',
      'largeMedium',
      'medium',
      'smallMedium',
      'small',
      'xSmall'
  ]
  </code></pre>
  
  <p>… and I have an object like this:</p>
  
  <pre><code>breakpoints = {
      "gtMedium": true,
      "xLarge": true,
      "gtLargeMedium": true,
      "giant": false,
      "small": false,
      "ltLargeMedium": false,
      "gtLarge": true,
      "xSmall": false,
      "largeMedium": false,
      "medium": false,
      "gtSmall": true,
      "large": false,
      "smallMedium": false
  }
  </code></pre>
  
  <p>I need to find the key in the object that’s <code>true</code> <em>and</em> exists in the array. For example, in this example above the value would be <code>xLarge</code> since <code>xLarge === true</code> in the object and exists in the <code>breakpoints</code> array.</p>
  
  <p>Any suggestions? Lodash is already a dependency in the project, if that helps.</p>