Sink sink = new Sink(4); // byte order insignificant here
    byte[] expected = {1, 2, 3, 4, 5, 6, 7, 8};
    sink.putByte((byte) 1);
    sink.putBytes(new byte[] {2, 3, 4, 5, 6});
    sink.putByte((byte) 7);
    sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);
  }

  public void testShort() {

    ByteBuffer bigEndian = ByteBuffer.wrap(bytes).order(ByteOrder.BIG_ENDIAN);
    assertEquals(
        hashFunction.newHasher().putBytes(littleEndian).hash(),
        hashFunction.newHasher().putBytes(bigEndian).hash());
    assertEquals(ByteOrder.LITTLE_ENDIAN, littleEndian.order());
    assertEquals(ByteOrder.BIG_ENDIAN, bigEndian.order());
  }

      ensureCapacity(Byte.BYTES);
      buffer.put(b);
      return this;
    }

    @Override
    public Hasher putBytes(byte[] bytes, int off, int len) {
      ensureCapacity(len);
      buffer.put(bytes, off, len);
      return this;
    }

    @Override
    public Hasher putBytes(ByteBuffer bytes) {
      ensureCapacity(bytes.remaining());
      buffer.put(bytes);
      return this;
    }

    ByteBuffer bigEndian = ByteBuffer.wrap(bytes).order(ByteOrder.BIG_ENDIAN);
    assertEquals(
        hashFunction.newHasher().putBytes(littleEndian).hash(),
        hashFunction.newHasher().putBytes(bigEndian).hash());
    assertEquals(ByteOrder.LITTLE_ENDIAN, littleEndian.order());
    assertEquals(ByteOrder.BIG_ENDIAN, bigEndian.order());
  }