title: Test file download, but suppress file contents being output on the command line
body: <p>I'm testing routes for downloading files in my Symfony application and everything is going fine, except for the ugly output of the PDF contents on the command line.</p>
  
  <p>For example I want to check that certain user role has access rights to download a PDF file:</p>
  
  <pre><code>$this-&gt;client-&gt;request('GET', '/media/download/1');
  $this-&gt;assertTrue($this-&gt;client-&gt;getResponse()-&gt;isSuccessful());
  </code></pre>
  
  <p>When this part of the test is hit, the contents of the PDF are print out on the command line, like this:</p>
  
  <blockquote>
    <p>31 / 31 (100%)%PDF-1.4 %äüöß 2 0 obj &lt;> stream x��TKk�@����s��&lt;�%0�8�
                           ��1�PzR����K�~��"j 9��ݙ�of��4
                _���c(��C���������@|�c�T�3%��������p�-�.
  </blockquote>
  
  <p>This is just for illustration, the actual output is much longer.</p>
  
  <p>This is a general issue and happens with other MIME types too.</p>
  
  <p>Is there any possibility to suppress the output?</p>