PowerMock忽略了我从方法返回

Question

我正在调用此方法返回一个空列表..

  public static List<String> getAttribute(@Nullable Subject subject, String key) {

      return Collections.emptyList();
    }

忽略此方法的简单性。

我有一个测试方法：

  @Test
  public void testGetRequesterGroupsOnSubject() {
      List<String> testData = new ArrayList<>();
      testData.add("admin");
    mockStatic(SecurityUtils.class);
    mock(SubjectUtils.class);
    doReturn(principalCollection).when(currentSubject).getPrincipals();
    doReturn(testData).when(SubjectUtils.getAttribute(currentSubject, SubjectUtils.ROLE_CLAIM_URI));
    assertEquals(sfa.getRequesterGroups(), new ArrayList<>());
  }

SubjectUtils是具有上述方法的类。但是，即使getAttribute返回一个空列表，我不应该期望这会重新调整我的字符串列表吗？ （TESTDATA）

当前错误：

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at 

E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, you naughty developer!
 3: you are stubbing the behaviour of another mock inside before 'thenReturn' instruction if completed