@Test
public void pipelineEmptyMapTest() {

    List<Map<String, String>> listWithEmptyMap = new LinkedList<>();
    listWithEmptyMap.add(new HashMap<String, String>());
    SingleValueAssignExtension assign = new SingleValueAssignExtension();
    Assign concreteAssignTag = new Assign();
    concreteAssignTag.setName("var_out_test");
    concreteAssignTag.setExpr("A");
    List<Map<String, String>> processedList = assign.pipelinePossibleStates(concreteAssignTag, listWithEmptyMap);
    Assert.assertEquals(1, processedList.size());
    Map<String, String> resultMap = processedList.get(0);
    Assert.assertEquals(1, resultMap.keySet().size());
    Assert.assertEquals("A", resultMap.get("var_out_test"));
}