*
   * @return the replacement characters, or {@code null} if no escaping was required
   */
  @Override
  protected final char @Nullable [] escape(int cp) {
    if (cp < replacementsLength) {
      char[] chars = replacements[cp];
      if (chars != null) {
        return chars;
      }
    }
    if (cp >= safeMin && cp <= safeMax) {
      return null;
    }
    return escapeUnsafe(cp);
  }

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

          @Override
          protected char[] escapeUnsafe(char 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).

        if (isEmpty(name)) {
            return name;
        }
        final char[] chars = name.toCharArray();
        if (chars.length >= 2 && Character.isUpperCase(chars[0]) && Character.isUpperCase(chars[1])) {
            return name;
        }
        chars[0] = Character.toLowerCase(chars[0]);
        return new String(chars);
    }

    /**
     * Capitalizes a string according to JavaBeans conventions.

   */
  @Override
  protected final char @Nullable [] escape(char c) {
    if (c < replacementsLength) {
      char[] chars = replacements[c];
      if (chars != null) {
        return chars;
      }
    }
    if (c >= safeMin && c <= safeMax) {
      return null;
    }
    return escapeUnsafe(c);
  }

  /**

  static long copyReaderToBuilder(Reader from, StringBuilder to) throws IOException {
    checkNotNull(from);
    checkNotNull(to);
    char[] buf = new char[DEFAULT_BUF_SIZE];
    int nRead;
    long total = 0;
    while ((nRead = from.read(buf)) != -1) {
      to.append(buf, 0, nRead);
      total += nRead;
    }
    return total;
  }

  /**

    String allMatchingChars = allMatchingChars(bitSet);
    char[] result = new char[STRING_LENGTH];
    // Fill with matching chars.
    for (int i = 0; i < result.length; i++) {
      result[i] = allMatchingChars.charAt(random.nextInt(allMatchingChars.length()));
    }
    // Replace some of chars by non-matching.
    int remaining = (int) ((100 - percentMatching) * result.length / 100.0 + 0.5);
    while (remaining > 0) {

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

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

                synonymMap.words.get(bytesReader.readVInt(), scratchBytes);
                if (scratchChars.chars.length < scratchBytes.length) {
                    scratchChars.chars = new char[scratchBytes.length];
                }
                scratchChars.length = UnicodeUtil.UTF8toUTF16(scratchBytes, scratchChars.chars);
                final String word = scratchChars.toString();
                int posInc = 0;

      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),

        assertNull(StringUtil.newStringUnsafe(null));
        char[] chars = new char[0];
        assertThat(StringUtil.newStringUnsafe(chars), is(""));
        chars = new char[] { 'a', 'b', 'c' };
        assertThat(StringUtil.newStringUnsafe(chars), is("abc"));
        chars = new char[] { 'a', 'b', 'c', ' ' };
        assertThat(StringUtil.newStringUnsafe(chars), is("abc "));
    }