title: Use namespace alias in twig
body: <p>I have a code that checks some entity constant in a twig template:</p>
  
  <pre><code>{% if logRecord.status is constant('App\\DealBundle\\Entity\\Deal::DEAL_STATE_MONEY_RESERVED') %}
  </code></pre>
  
  <p>But it is so embarrassing to use such a long class name everytime. Is there any way to make a namespace alias in twig? Something like:</p>
  
  <pre><code>{% use App\\DealBundle\\Entity\\Deal %}
  {% if logRecord.status is constant('Deal::DEAL_STATE_MONEY_RESERVED') %}
  </code></pre>
  
  <p>Or I always need to write full class names?</p>