@Test
  public void testHashIndexRemoveAll() throws Exception {
    int numEntries = 100;
    setupHashIndexSet(numEntries);

    assertEquals(numEntries, his.size());
    his.removeAll(portfolioSet);
    assertTrue(his.isEmpty());
  }
Test remove where we look for an instance that is not at the specified index slot
geode-core/src/test/java/org/apache/geode/cache/query/internal/index/HashIndexSetJUnitTest.java