@Test
  public void testCompareNullSd()
  {
    assertThat(new MetaStoreServerUtils.StorageDescriptorKey("a", null),
        is(new MetaStoreServerUtils.StorageDescriptorKey("a", null)));
    // Different locations produce different objects
    assertThat(new MetaStoreServerUtils.StorageDescriptorKey("a", null),
        IsNot.not(equalTo(new MetaStoreServerUtils.StorageDescriptorKey("b", null))));
  }
Two StorageDescriptorKey objects with null storage descriptors should be
equal iff the base location is equal.
standalone-metastore/metastore-server/src/test/java/org/apache/hadoop/hive/metastore/utils/TestMetaStoreServerUtils.java