title: Tracy debugging library throwing syntax error
body: <p>I am trying to use this library <a href="https://github.com/nette/tracy" rel="nofollow">https://github.com/nette/tracy</a> for enabling PHP debuger on my site.</p>
  
  <p>I've downloaded the <code>src</code> folder and included <code>tracy.php</code> in my app but now I get this error:</p>
  
  <pre><code>Parse error: syntax error, unexpected '[' in /data/web/virtuals/.../src/Tracy/Bar.php on line 17
  </code></pre>
  
  <p>This is how Bar.php looks like up to line 17:</p>
  
  <pre><code>&lt;?php
  
  /**
   * This file is part of the Tracy (https://tracy.nette.org)
   * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
   */
  
  namespace Tracy;
  
  
  /**
   * Debug Bar.
   */
  class Bar
  {
      /** @var IBarPanel[] */
      private $panels = [];
  </code></pre>
  
  <p>What am I doing wrong? Do I need something else to run Tracy? On <a href="https://tracy.nette.org/" rel="nofollow">https://tracy.nette.org/</a> they say all you need to do is include tracy.php...</p>