Added comments to the Chunk interface
Added comments to the Chunk interface

Signed-off-by: Marco Pracucci <3829486b93ec44395f0b980424bae9b6fb07b7bc@pracucci.com>

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