addToHash(hasher, spec.getDisallowedPackagePrefixes());
        return hasher.hash();
    }

    private static void addToHash(Hasher hasher, Set<String> items) {
        int count = items.size();
        hasher.putInt(count);
        if (count == 0) {
            return;
        }
        String[] sortedItems = items.toArray(new String[count]);
        Arrays.sort(sortedItems);
        for (String item : sortedItems) {

    /**
     * Feed a single byte into the hasher.
     */
    void putByte(byte value);

    /**
     * Feed an integer byte into the hasher.
     */
    void putInt(int value);

    /**
     * Feed a long value byte into the hasher.
     */
    void putLong(long value);

    /**
     * Feed a double value into the hasher.
     */
    void putDouble(double value);

  @CanIgnoreReturnValue
  public final Hasher putChar(char c) {
    buffer.putChar(c);
    munchIfFull();
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putInt(int i) {
    buffer.putInt(i);
    munchIfFull();
    return this;
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putLong(long l) {
    buffer.putLong(l);
    munchIfFull();
    return this;

    return new BufferingHasher(expectedInputSize);
  }

  @Override
  public HashCode hashInt(int input) {
    return hashBytes(ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(input).array());
  }

  @Override
  public HashCode hashLong(long input) {
    return hashBytes(ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(input).array());
  }

  @Override

    HashCode unused = sink.hash();
    sink.assertInvariants(2);
    sink.assertBytes(new byte[] {1, 2, 0, 0}); // padded with zeros
  }

  public void testInt() {
    Sink sink = new Sink(4);
    sink.putInt(0x04030201);
    HashCode unused = sink.hash();
    sink.assertInvariants(4);
    sink.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    Sink sink = new Sink(8);

        hasher.putString(functionalInterfaceClass);
        hasher.putString(implClass);
        hasher.putString(implMethodName);
        hasher.putString(implMethodSignature);
        hasher.putInt(implMethodKind);
    }

    @Nullable
    @Override
    public HashCode getClassLoaderHash() {
        return classLoaderHash;
    }

    public String getFunctionalInterfaceClass() {

    TestHasher hasher = new TestHasher();
    hasher.putShort((short) 0x0201);
    hasher.assertBytes(new byte[] {1, 2});
  }

  public void testInt() {
    TestHasher hasher = new TestHasher();
    hasher.putInt(0x04030201);
    hasher.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    TestHasher hasher = new TestHasher();
    hasher.putLong(0x0807060504030201L);

    return new BufferingHasher(expectedInputSize);
  }

  @Override
  public HashCode hashInt(int input) {
    return hashBytes(ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(input).array());
  }

  @Override
  public HashCode hashLong(long input) {
    return hashBytes(ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(input).array());
  }

  @Override

      buffer.order(ByteOrder.LITTLE_ENDIAN);
      while (buffer.remaining() >= 4) {
        putInt(buffer.getInt());
      }
      while (buffer.hasRemaining()) {
        putByte(buffer.get());
      }
      buffer.order(bo);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Hasher putInt(int i) {
      update(4, i);
      return this;
    }

    @CanIgnoreReturnValue

        sha1.putString("The quick brown fox jumps over the lazy dog", Charsets.UTF_8)
            .hash()
            .toString());
    assertThrows(IllegalStateException.class, () -> sha1.putInt(42));
  }

  public void testHashTwice() {
    Hasher sha1 = Hashing.sha1().newHasher();

    assertEquals(
        "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12",