docs: def with_(context, nodelist, val):
      """
      Adds a value to the context (inside of this block) for caching and easy
      access.
  
      For example::
  
          {% with person.some_sql_method as total %}
              {{ total }} object{{ total|pluralize }}
          {% endwith %}
      """
      context.push()
      context[self.name] = val
      output = nodelist.render(context)
      context.pop()
      return output