in src/main/scala/com/spotify/bdrc/pipeline/Count.scala [47:55]
def scio(input: SCollection[Rating]): SCollection[Long] =
input.count
// ## Scio with Algebird `Aggregator`
def scioWithAlgebird(input: SCollection[Rating]): SCollection[Long] = {
import com.twitter.algebird.Aggregator.size
input
.aggregate(size)
}