OperationHistoryManager { @SuppressWarnings("unchecked") public <A extends ClusterManagementOperation<V>, V extends OperationResult> OperationState<A, V> get( String opId) { expireHistory(); return (OperationState<A, V>) operationStateStore.get(opId); } OperationHistoryManager(
      OperationStateStore operationStateStore, InternalCache cache);  OperationHistoryManager(Duration keepCompleted,
      OperationStateStore operationStateStore,
      InternalCache cache); @SuppressWarnings("unchecked") OperationState<A, V> get(
      String opId); String recordStart(ClusterManagementOperation<?> op, String locator); void recordEnd(String opId, OperationResult result, Throwable cause); List<OperationState<A, V>> list(
      A opType);  }
@Test public void idNotFound() { assertThat(history.get("foo")).isNull(); }