title: Mark a Python class as abstract by hand for Doxygen
body: <p>I'm using Doxygen to generate a documentation for a Python project. </p>
  
  <p>I want to mark a certain Python 2 class as <em>abstract</em>, is there any default way to get Doxygen to do this for me (some command like <em>@abstract</em> in the class docstring), or do I have to create a regular remark?</p>