elixir event handler for tradeline validation

elixir_validation.ex

defmodule Sample.EventHandler do
  alias KaufmannEx.Schemas.Event

  def given_event(%Event{name: :"loan.tradeline", payload: payload} = event) do

    {state: state} = payload

    if Enum.member?(["CO", "CA", "KS", FL"], state) do
      {:ok, "loan.tradeline.validation.state", payload.tracking_number}
    else
      ErrorPublisher.publish(:"loan.tradeline.validation.error", "loan.tradeline.validation.state.invalid", payload.tracking_number, event.meta)
      {:error, "loan.tradeline.validation.state", payload.tracking_number}
    end
  end 
  
end