No dec.DisallowUnknownFields() function

[aixeshunter]

In prometheus/discovery/targetgroup/targetgroup.go file that line 81:

	dec := json.NewDecoder(bytes.NewReader(b))
	dec.DisallowUnknownFields()
	if err := dec.Decode(&g); err != nil {
		return err
	}

the dec.DisallowUnknownFields() functon call is error in my IDE.
Is that a BUG?

[simonpasquier]

DisallowUnknownFields() has been added to the encoding/json package in Go 1.10. You need preferably Go 1.11.2 to build Prometheus.

[aixeshunter]

it works, thanks