@Test public void testFixedDelayRestartStrategy() { int numberRestarts = 10; long restartDelay = 10; FixedDelayRestartStrategy fixedDelayRestartStrategy = new FixedDelayRestartStrategy(numberRestarts, restartDelay); ExecutionGraph executionGraph = mock(ExecutionGraph.class); when(executionGraph.getFutureExecutor()) .thenReturn(ExecutionContext$.MODULE$.fromExecutor(MoreExecutors.directExecutor())); while (fixedDelayRestartStrategy.canRestart()) { fixedDelayRestartStrategy.restart(executionGraph); } Mockito.verify(executionGraph, Mockito.times(numberRestarts)).restart(); }