docs: public static JsExpr genJsExprUsingSoySyntax(Operator op, List<JsExpr> operandJsExprs) {
      List<Expression> operands =
          Lists.transform(operandJsExprs, input -> fromExpr(input, ImmutableList.<GoogRequire>of()));
      return Expression.operation(op, operands).assertExpr();
    }