@NullUnmarked
public class HashingInputStreamTest extends TestCase {
  private Hasher hasher;
  private HashFunction hashFunction;
  private static final byte[] testBytes = new byte[] {'y', 'a', 'm', 's'};
  private ByteArrayInputStream buffer;

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

@NullUnmarked
public class HashingInputStreamTest extends TestCase {
  private Hasher hasher;
  private HashFunction hashFunction;
  private static final byte[] testBytes = new byte[] {'y', 'a', 'm', 's'};
  private ByteArrayInputStream buffer;

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

 */
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue
  public final Hasher putBoolean(boolean b) {
    return putByte(b ? (byte) 1 : (byte) 0);
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putDouble(double d) {
    return putLong(Double.doubleToRawLongBits(d));
  }

  @Override
  @CanIgnoreReturnValue
  public final Hasher putFloat(float f) {

    }
  }

  /**
   * Hashes the contents of this byte source using the given hash function.
   *
   * @throws IOException if an I/O error occurs while reading from this source
   */
  public HashCode hash(HashFunction hashFunction) throws IOException {
    Hasher hasher = hashFunction.newHasher();
    copyTo(Funnels.asOutputStream(hasher));
    return hasher.hash();
  }

  /**

    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);
    hasher.assertBytes(new byte[] {1, 2, 3, 4, 5, 6, 7, 8});

 */
@NullUnmarked
public class HashingOutputStreamTest extends TestCase {
  private Hasher hasher;
  private HashFunction hashFunction;
  private final ByteArrayOutputStream buffer = new ByteArrayOutputStream();

  @SuppressWarnings("DoNotMock")
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    hasher = mock(Hasher.class);
    hashFunction = mock(HashFunction.class);

    assertThrows(IllegalStateException.class, () -> hasher.putInt(42));
  }

  public void testHashTwice() {
    Hasher hasher = sha512().newHasher();

    assertThat(
            hasher
                .putString("The quick brown fox jumps over the lazy dog", UTF_8)
                .hash()
                .toString())
        .isEqualTo(

    }

    @Override
    public Hasher putByte(byte b) {
      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) {

        original_header_info = original_header_permalinks[header_no]

        if header_info["hashes"] != original_header_info["hashes"]:
            raise ValueError(
                "Header levels do not match between document and original document"
                f" (found {header_info['hashes']}, expected {original_header_info['hashes']})"
                f" for header №{header_no + 1} in line {header_info['line_no']}"
            )

  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */
  protected void update(byte[] b, int off, int len) {
    for (int i = off; i < off + len; i++) {
      update(b[i]);
    }
  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {