title: Error with custom inclusion_tag, can't find file
body: <p>I'm trying to write a custom inclusion_tag in django.</p>
  
  <p>Following the example on <a href="http://docs.djangoproject.com/en/dev/howto/custom-template-tags/" rel="nofollow noreferrer">http://docs.djangoproject.com/en/dev/howto/custom-template-tags/</a></p>
  
  <p>I'm just writing </p>
  
  <pre><code>@register.inclusion_tag('test.html')
  </code></pre>
  
  <p>where test.html is a file in the same directory ( apps/my_app/templatetags) as the .py file which defines it.</p>
  
  <p>But I'm getting a</p>
  
  <pre><code>TemplateDoesNotExist: test.html
  </code></pre>
  
  <p>error. Which I suppose is because django can't find the template.</p>
  
  <p>How could I check this? And what determines where django looks for the file?</p>