dopple

defprotocol Dopple.Aggregator do
  @moduledoc """
    A mechanism that listens to a set of measurements in order to act on the results
  """

  alias Dopple.Measurement

  @spec add_measurement(__MODULE__.t(), Measurement.t()) :: {:ok, __MODULE__.t()} | {:error, any}
  def add_measurement(agg, measurement)

  @spec consumer(__MODULE__.t()) :: {:ok, GenStage.stage()} | {:error, any}
  def consumer(agg)
end