in pekko-sample-sharding-scala/killrweather/src/main/scala/sample/killrweather/JacksonSerializers.scala [17:24]
override def serialize(value: WeatherStation.DataType, gen: JsonGenerator, provider: SerializerProvider): Unit = {
val strValue = value match {
case WeatherStation.DataType.Dewpoint => "d"
case WeatherStation.DataType.Temperature => "t"
case WeatherStation.DataType.Pressure => "p"
}
gen.writeString(strValue)
}