Trouble with sum() and by(). Need to sum decimal in tag, and then show

[Yevhenii Hrabovskyi]

I have metric:

 test_metric_name{app="test",product="asap_r", service="traas", team="billing", value="0.0"}.

 And query: 

sum(rate( test_metric_name  [$__rate_interval]) * $__interval_ms) by (value).

I need to calculate sum of tag `value` in interval, and show it in grafana dashboard, but got a lot of duplicated legend with name `value`. 

iI i try to rename it in options(set custom legend name) - there is same duplicate legend but with same name