docs: def truncatechars(value, num, end_text="..."):
      """Truncate string on character boundary.
  
      .. note::
          Django ticket `5025 <http://code.djangoproject.com/ticket/5025>`_ has a
          patch for a more extensible and robust truncate characters tag filter.
  
      Example::
  
          {{ my_variable|truncatechars:22 }}
  
      :param value: Value to truncate.
      :type  value: ``string``
      :param num: Number of characters to trim to.
      :type  num: ``int``
      """
      length = None
      try:
          length = int(num)
      except ValueError:
          pass
  
      if length is not None and len(value) > length:
          return value[:length - len(end_text)] + end_text
  
      return value