code: @Override
      public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
          log.debug("In evaluate() of DEFINE function. Args = {}", Arrays.toString(args));
          
          return new StringEval(DefineFunction.class.getAnnotation(CustomFunctionMeta.class).value());
      }
docs: This function does nothing, since it should never be evaluated.
  DEFINE function is a spreadsheet metadata and it cannot have a value.