@Test
public void getUserName_Success() throws Exception {

    String token = "4EpPYDSfgN2D4Gf7UmNO3nuL";
    String username = "testuser";
    Response response = getMockResponse(HttpStatus.OK, true, username);
    ResponseEntity<String> responseEntityExpected = ResponseEntity.status(HttpStatus.OK).body("{\"data\":{\"username\": \"" + username.toLowerCase() + "\"}}");
    when(OIDCUtil.getUserName(Mockito.anyString())).thenReturn(username);
erDetails userDetails = new UserDetails();
erDetails.setUsername("testuser");
    ResponseEntity<String> responseEntity = oidcAuthService.getUserName(userDetails);
    assertEquals(HttpStatus.OK, responseEntity.getStatusCode());
    assertEquals(responseEntityExpected, responseEntity);
}