code: def _include_file(context, uri, calling_uri, **kwargs):
      
  
      template = _lookup_template(context, uri, calling_uri)
      (callable_, ctx) = _populate_self_namespace(
                                  context._clean_inheritance_tokens(),
                                  template)
      callable_(ctx, **_kwargs_for_include(callable_, context._data, **kwargs))
docs: locate the template from the given uri and include it in
      the current output.