docs: private boolean vForVariableAndKeyAndIndex(String loopVariablesDefinition,
        TemplateParserContext context) {
      Matcher matcher = VFOR_VARIABLE_AND_KEY_AND_INDEX.matcher(loopVariablesDefinition);
      if (matcher.matches()) {
        initLoopVariable(matcher.group(1), matcher.group(2), context);
        initKeyVariable(matcher.group(3), context);
        initIndexVariable(matcher.group(4), context);
        return true;
      }
  
      return false;
    }