// stage X does not contain task A anymore
assertNull(caseInstance.findCaseExecution("A"));
// stage X does not contain task B anymore
assertNull(caseInstance.findCaseExecution("B"));
// stage X does not contain task X anymore
assertNull(caseInstance.findCaseExecution("X"));
// stage X has only one child
assertEquals(0, ((CaseExecutionImpl) caseInstance).getCaseExecutions().size());
// case instance is completed