See,
$ gometalinter --vendor --disable-all --enable=megacheck --disable=gotype --deadline 6m ./...
pkg/tsdb/elasticsearch/client/client_test.go:28:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)
pkg/tsdb/elasticsearch/client/client_test.go:39:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)
pkg/tsdb/elasticsearch/client/client_test.go:51:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)
pkg/tsdb/elasticsearch/client/client_test.go:63:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)
pkg/tsdb/elasticsearch/client/client_test.go:76:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)
pkg/tsdb/elasticsearch/client/client_test.go:89:25:warning: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012) (megacheck)