public void next(int n) {
        pos += n;
    }

    public boolean lookingAt(char c) {
        return input.charAt(pos) == c;
    }

    public boolean lookingAt(CharSequence prefix) {
        int i = 0;
        int cpos = pos;
        while (i < prefix.length() && cpos < input.length()) {
            if (prefix.charAt(i) != input.charAt(cpos)) {
                return false;
            }
            i++;

    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));

    static final int EOF = -1;

    static final char PROPERTY_START = '.';

    static final char INDEXED_START = '[';

    static final char INDEXED_END = ']';

    static final char MAPPED_START = '(';

    static final char MAPPED_END = ')';

    static class Tokenizer {
        final String expression;

        int idx;

        assertNull(result);
    }

    @Test
    public void test_smartSummary_exactlyAtBudget() {
        // omitMarker = "\n...[omitted]...\n" (18 chars), suffix="" (no sources), bodyBudget = 500 - 0 - 18 = 482
        // Content of 482 chars is <= bodyBudget, so returned with suffix (empty) appended as-is
        final String content = "X".repeat(482);
        final ChatMessage msg = ChatMessage.assistantMessage(content);

          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).

                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;

        assertEquals(testStringTrue.length() + 1, unicodeStringTrue.buffer.length, "Buffer length should include zterm");
        for (int i = 0; i < testStringTrue.length(); i++) {
            assertEquals(testStringTrue.charAt(i), (char) unicodeStringTrue.buffer[i], "Character mismatch");
        }
        assertEquals(0, unicodeStringTrue.buffer[testStringTrue.length()], "Last character should be zero");

    checkNotNull(a);
    checkNotNull(b);

    int maxPrefixLength = min(a.length(), b.length());
    int p = 0;
    while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
      p++;
    }
    if (validSurrogatePairAt(a, p - 1) || validSurrogatePairAt(b, p - 1)) {
      p--;
    }
    return a.subSequence(0, p).toString();
  }

  /**

  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;
  }

  /**

      int slen = s.length();
      for (int index = 0; index < slen; index++) {
        char c = s.charAt(index);
        if (c < replacements.length && replacements[c] != null) {
          return escapeSlow(s, index);
        }
      }
      return s;
    }

    @Override
    protected char @Nullable [] escape(char c) {
      return c < replaceLength ? replacements[c] : null;
    }
  }