### Question:
CallActivityPropertyWriter extends MultipleInstanceActivityPropertyWriter { public void setAsync(Boolean async) { CustomElement.async.of(activity).set(async); } CallActivityPropertyWriter(CallActivity activity, VariableScope variableScope, Set<DataObject> dataObjects); void setOnEntryAction(OnEntryAction onEntryAction); void setOnExitAction(OnExitAction onExitAction); void setIndependent(Boolean independent); void setAbortParent(Boolean abortParent); void setWaitForCompletion(Boolean waitForCompletion); void setAsync(Boolean async); void setCalledElement(String value); void setCase(Boolean isCase); void setAdHocAutostart(boolean autoStart); void setSlaDueDate(SLADueDate slaDueDate);  }### Answer:
@Test public void testSetIsAsync() { tested.setAsync(Boolean.TRUE); assertTrue(CustomElement.async.of(tested.getFlowElement()).get()); }