new UnicodeEscaper() {
          // Canonical escaper method that only escapes lower case ASCII letters.
          @Override
          protected char @Nullable [] escape(int cp) {
            return ('a' <= cp && cp <= 'z') ? new char[] {Character.toUpperCase((char) cp)} : null;
          }
          // Inefficient implementation that defines all letters as escapable.
          @Override

    // Exhaustively check all mappings (an int index avoids wrapping).
    for (int n = 0; n < replacementArray.length; ++n) {
      char c = (char) n;
      if (replacementArray[n] != null) {
        assertEquals(map.get(c), new String(replacementArray[n]));
      } else {
        assertFalse(map.containsKey(c));
      }
    }
  }

    this.source = factory.createSource(data);
  }

  public void testOpenStream() throws IOException {
    Reader reader = source.openStream();

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());

@ElementTypesAreNonnullByDefault
public class TreeTraverserTest extends TestCase {
  private static class Node {
    final char value;

    Node(char value) {
      this.value = value;
    }
  }

  private static final class Tree extends Node {
    final List<Tree> children;

    public Tree(char value, Tree... children) {
      super(value);
      this.children = Arrays.asList(children);
    }
  }

  }

  /**
   * Reads a char as specified by {@link DataInputStream#readChar()}, except using little-endian
   * byte order.
   *
   * @return the next two bytes of the input stream, interpreted as a {@code char} in little-endian
   *     byte order
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // to skip some bytes
  @Override
  public char readChar() throws IOException {

          // TODO(lukes): in a real implementation we would need to handle overflow conditions
          int maxChars = (int) (size.get().intValue() * cs.newDecoder().maxCharsPerByte());
          char[] buffer = new char[maxChars];
          int bufIndex = 0;
          int remaining = buffer.length;
          try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
            int nRead = 0;

          // TODO(lukes): in a real implementation we would need to handle overflow conditions
          int maxChars = (int) (size.get().intValue() * cs.newDecoder().maxCharsPerByte());
          char[] buffer = new char[maxChars];
          int bufIndex = 0;
          int remaining = buffer.length;
          try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
            int nRead = 0;

   * false} for {@code boolean} and {@code '\0'} for {@code char}. For non-primitive types and
   * {@code void}, {@code null} is returned.
   */
  @SuppressWarnings("unchecked")
  @CheckForNull
  public static <T> T defaultValue(Class<T> type) {
    checkNotNull(type);
    if (type.isPrimitive()) {
      if (type == boolean.class) {
        return (T) Boolean.FALSE;
      } else if (type == char.class) {
        return (T) Character.valueOf('\0');

    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    data = sb.toString();
  }

  @Benchmark
  public long timeCopy(int reps) throws IOException {
    long r = 0;
    final String localData = data;

    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    data = sb.toString();
  }

  @Benchmark
  public long timeCopy(int reps) throws IOException {
    long r = 0;
    final String localData = data;