title: Cannot use 'Object' as class name as it is reserved
body: <p>I'm trying to update my composer with <strong>composer self-update</strong> but i get this error </p>
  
  <pre><code>composer self-update
  Updating to version 6034c2af01e264652a060e57f1e0288b4038a31a.
      Downloading: 100%         
  
  Fatal error: Cannot use 'Object' as class name as it is reserved in phar:///usr/local/bin/composer/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/Object.php on line 18
  </code></pre>
  
  <p>I'm using macOS 10.15.2</p>
  
  <p>trying to see other answers but cannot find anything related to this.</p>