     """
 
     Observer.configure(pid, [{NoopPlugin, {"file:///", bmf}},{Take, 2}])
+    TestListener.clear(listener)
     :ok = Observer.run(pid)
 
     wait_for fn -> length(TestListener.get(listener)) >= 3 end

    """

    Observer.configure(pid, [{Take, 0}, {NoopPlugin, {"file:///", bmf}}])
    :ok = Observer.run(pid)

    wait_for fn -> length(TestListener.get(listener)) >= 3 end


  alias Baumeister.Test.TestListener
  alias Experimental.GenStage
  alias Baumeister.EventCenter

  alias Baumeister.Observer
  alias Baumeister.Observer.FailPlugin
  alias Baumeister.Observer.NoopPlugin
  alias Baumeister.Observer.Take
  alias Baumeister.Observer.Delay

  def wait_for(pred) do
    case pred.() do
