#vulnerable code 
                              @Test
  public void testSyncRefresh() throws IOException {
    initialize(HeaderCacheElement.TOKEN_STALENESS_MS + 1);
    Assert.assertEquals(CacheState.Good, underTest.headerCache.getCacheState());
  } 
                            #location 3 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                              @Test
  public void testSyncRefresh() throws IOException {
    initialize(HeaderCacheElement.TOKEN_STALENESS_MS + 1);
    Assert.assertEquals(CacheState.Good, underTest.headerCache.getCacheState());
    Assert.assertFalse(underTest.isRefreshing());
  }