title: When i change file_get_contents to WP_Filesystem it doesn't work
body: <p>I am working on a wordpress theme. It is almost complete. When i check it in theme-check plugin it give the warning</p>
  
  <pre><code>WARNING: file_get_contents was found in the file sources.php File operations
  should use the WP_Filesystem methods instead of direct PHP filesystem calls.
  Line 84: $fonts = file_get_contents(dirname(__FILE__) . '/gwf.json');
  </code></pre>
  
  <p>Then i change <code>file_get_contents</code> to <code>WP_Filesystem</code> but it not getting the value or not working.</p>
  
  <p>Here is the code of line 84:</p>
  
  <pre><code>function vp_get_gwf_family()
  {
      $fonts = file_get_contents(dirname(__FILE__) . '/gwf.json');
      $fonts = json_decode($fonts);
  
      $fonts = array_keys(get_object_vars($fonts));
  
      foreach ($fonts as $font)
      {
          $result[] = array('value' =&gt; $font, 'label' =&gt; $font);
      }
  
      return $result;
  }
  </code></pre>