### Question:
ExperimentManager { Collection<Experiment> getAllExperiments () { return allExperiments; }  void setExperimentBackoffPeriod(Duration experimentBackoffPeriod); boolean areExperimentsInProgress();  }### Answer:
@Test public void getAllExperiments () { assertThat(experimentManager.getAllExperiments(), emptyIterable()); Experiment experiment = experimentManager.addExperiment(mock(Experiment.class)); assertThat(experimentManager.getAllExperiments(), containsInAnyOrder(experiment)); }