* instance that is ready to receive data. Example:
   *
   * <pre>{@code
   * HashFunction hf = Hashing.md5();
   * HashCode hc = hf.newHasher()
   *     .putLong(id)
   *     .putBoolean(isActive)
   *     .hash();
   * }</pre>
   */
  Hasher newHasher();

  /**
   * Begins a new hash code computation as {@link #newHasher()}, but provides a hint of the expected

    PUT_BOOLEAN() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        boolean value = random.nextBoolean();
        for (PrimitiveSink sink : sinks) {
          sink.putBoolean(value);
        }
      }
    },
    PUT_BYTE() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        int value = random.nextInt();

    PUT_BOOLEAN() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        boolean value = random.nextBoolean();
        for (PrimitiveSink sink : sinks) {
          sink.putBoolean(value);
        }
      }
    },
    PUT_BYTE() {
      @Override
      void performAction(Random random, Iterable<? extends PrimitiveSink> sinks) {
        int value = random.nextInt();