in src/main/scala/com/spotify/bdrc/pipeline/CountUsers.scala [40:46]
def scaldingWithAlgebird(input: TypedPipe[Rating]): TypedPipe[Long] = {
import com.twitter.algebird.Aggregator.count
input
// Aggregate globally into a single `Long`
.aggregate(count(_.user == "Smith"))
.toTypedPipe
}