chars.add(randomAlpha());
    }
    for (int i = 0; i < nonAlpha; i++) {
      chars.add(randomNonAlpha());
    }
    Collections.shuffle(chars, random);
    char[] array = Chars.toArray(chars);
    this.testString = new String(array);
  }

  private char randomAlpha() {
    return ALPHA.charAt(random.nextInt(ALPHA.length()));
  }

  private char randomNonAlpha() {

        char c0 = input.charAt(i);
        char c1 = input.charAt(i + 1);
        char c2 = input.charAt(i + 2);
        char c3 = input.charAt(i + 3);
        if (c0 < 0x80 && c1 < 0x80 && c2 < 0x80 && c3 < 0x80) {
          int k1 = c0 | (c1 << 8) | (c2 << 16) | (c3 << 24);
          k1 = mixK1(k1);
          h1 = mixH1(h1, k1);
          i += 4;
          len += 4;
        } else {
          break;
        }

  }

  private static void assertPutString(char[] chars) {
    Hasher h1 = new NonStreamingVersion().newHasher();
    Hasher h2 = new NonStreamingVersion().newHasher();
    String s = new String(chars);
    // this is the correct implementation of the spec
    for (int i = 0; i < s.length(); i++) {
      h1.putChar(s.charAt(i));
    }
    h2.putUnencodedChars(s);
    assertEquals(h1.hash(), h2.hash());
  }

  }

  private static void assertPutString(char[] chars) {
    Hasher h1 = new NonStreamingVersion().newHasher();
    Hasher h2 = new NonStreamingVersion().newHasher();
    String s = new String(chars);
    // this is the correct implementation of the spec
    for (int i = 0; i < s.length(); i++) {
      h1.putChar(s.charAt(i));
    }
    h2.putUnencodedChars(s);
    assertEquals(h1.hash(), h2.hash());
  }

                new char[] {(char) 2, (char) 3, (char) 4}))
        .isEqualTo(2);
    assertThat(
            Chars.indexOf(
                new char[] {(char) 2, (char) 2, (char) 3, (char) 4, (char) 2, (char) 3, (char) 4},
                new char[] {(char) 2, (char) 3, (char) 4}))
        .isEqualTo(1);
    assertThat(
            Chars.indexOf(

      HashFunction hashFunction, Random random) {
    int size = random.nextInt(8) + 1;
    char[] chars = new char[size];
    for (int i = 0; i < chars.length; i++) {
      chars[i] = random.nextBoolean() ? randomLowSurrogate(random) : randomHighSurrogate(random);
    }
    String string = new String(chars);
    assertEquals(
        hashFunction.hashUnencodedChars(string),

          private final char[] unknown = new char[] {'?'};

          @Override
          protected char[] escapeUnsafe(int c) {
            return unknown;
          }
        };
    EscaperAsserts.assertBasic(replacingEscaper);

    // Replacements are applied first regardless of whether the character is in
    // the safe range or not ('&' is a safe char while '\t' and '\n' are not).
    assertEquals(

    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(Arrays.asList(elements));
      return Lists.charactersOf(String.copyValueOf(chars));
    }
  }

  public static class CharactersOfCharSequenceGenerator extends TestCharacterListGenerator {
    @Override
    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(Arrays.asList(elements));

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice
    // TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing
    for (int i = 0; i < 8; i++) {
      builder.append((char) reader.read());
    }
    assertEquals(expected, builder.toString());