sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);
  }

  public void testShort() {
    Sink sink = new Sink(4);
    sink.putShort((short) 0x0201);
    HashCode unused = sink.hash();
    sink.assertInvariants(2);
    sink.assertBytes(new byte[] {1, 2, 0, 0}); // padded with zeros
  }

  public void testInt() {

      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testEntrySet() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    assertInvariants(map);

    Set<Entry<K, V>> entrySet = map.entrySet();
    K unmappedKey;
    V unmappedValue;

    HashTestUtils.assertInvariants(Hashing.sha512());
    assertEquals("Hashing.sha512()", Hashing.sha512().toString());
  }

  public void testCrc32() {
    HashTestUtils.assertInvariants(Hashing.crc32());
    assertEquals("Hashing.crc32()", Hashing.crc32().toString());
  }

  public void testAdler32() {
    HashTestUtils.assertInvariants(Hashing.adler32());

    sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);
  }

  public void testShort() {
    Sink sink = new Sink(4);
    sink.putShort((short) 0x0201);
    HashCode unused = sink.hash();
    sink.assertInvariants(2);
    sink.assertBytes(new byte[] {1, 2, 0, 0}); // padded with zeros
  }

  public void testInt() {

    HashTestUtils.assertInvariants(Hashing.sha512());
    assertEquals("Hashing.sha512()", Hashing.sha512().toString());
  }

  public void testCrc32() {
    HashTestUtils.assertInvariants(Hashing.crc32());
    assertEquals("Hashing.crc32()", Hashing.crc32().toString());
  }

  public void testAdler32() {
    HashTestUtils.assertInvariants(Hashing.adler32());

      assertFalse(map.containsKey(keyToRemove));
      assertEquals(initialSize - 1, map.size());
    } else {
      assertThrows(UnsupportedOperationException.class, () -> map.remove(keyToRemove));
    }
    assertInvariants(map);
  }

        assertEquals(initialSize - 1, map.size());
      } else {
        assertThrows(UnsupportedOperationException.class, () -> map.remove(keyToRemove));
      }
      assertInvariants(map);
    }
  }

  abstract static class RowMapTests extends MapMapTests {
    RowMapTests(
        boolean allowsNullValues,
        boolean supportsRemove,
        boolean supportsClear,

        }
      }
    }
  }

  /**
   * Checks that a Hasher returns the same HashCode when given the same input, and also that the
   * collision rate looks sane.
   */
  static void assertInvariants(HashFunction hashFunction) {
    int objects = 100;
    Set<HashCode> hashcodes = Sets.newHashSetWithExpectedSize(objects);
    Random random = new Random(314159);
    for (int i = 0; i < objects; i++) {