testHashing512Large() {
    const hasher = new Sha512();
    hasher.update((new Array(1000000)).fill(0));
    const digest = hasher.digest();
    const expected = crypt.hexToByteArray(
        'ce044bc9fd43269d5bbc946cbebc3bb711341115cc4abdf2edbc3ff2c57ad4b1' +
        '5deb699bda257fea5aef9c6e55fcf4cf9dc25a8c3ce25f2efe90908379bff7ed');
    assertElementsEquals(expected, digest);
  }
Test one really large string using SHA512