Update doc comment
Update doc comment

Signed-off-by: Fabian Reinartz <bb86cc68560718128c801bf7438361ace07bbc0d@google.com>

keegancsmith/prometheus,alileza/prometheus,Gouthamve/prometheus,Gouthamve/tsdb,kangwoo/prometheus,keegancsmith/prometheus,prometheus/tsdb,keegancsmith/prometheus,alileza/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,Gouthamve/prometheus,kangwoo/prometheus,prometheus/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,prometheus/prometheus,Gouthamve/prometheus,alileza/prometheus,prometheus/prometheus,kangwoo/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus