}
        sb.append(comp);
      }
      dummy ^= sb.toString().length();
    }
    return dummy;
  }

  /**
   * Similar to the above, but keeps a boolean flag rather than checking for the string accumulated
   * so far being empty. As a result, it does not have the above-mentioned bug.
   */
  @Benchmark
  int booleanIfFirst(int reps) {
    int dummy = 0;

        }
        sb.append(comp);
      }
      dummy ^= sb.toString().length();
    }
    return dummy;
  }

  /**
   * Similar to the above, but keeps a boolean flag rather than checking for the string accumulated
   * so far being empty. As a result, it does not have the above-mentioned bug.
   */
  @Benchmark
  int booleanIfFirst(int reps) {
    int dummy = 0;

 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

  public static CommonPattern compile(String pattern) {

 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

  public static CommonPattern compile(String pattern) {

    return new JdkMatcher(pattern.matcher(t));
  }

  @Override
  public String pattern() {
    return pattern.pattern();
  }

  @Override
  public int flags() {
    return pattern.flags();
  }

  @Override
  public String toString() {
    return pattern.toString();
  }

  private static final class JdkMatcher extends CommonMatcher {
    final Matcher matcher;

  private static final char[] UPPER_HEX_DIGITS = "0123456789ABCDEF".toCharArray();

  /** If true we should convert space to the {@code +} character. */
  private final boolean plusForSpace;

  /**
   * An array of flags where for any {@code char c} if {@code safeOctets[c]} is true then {@code c}
   * should remain unmodified in the output. If {@code c >= safeOctets.length} then it should be
   * escaped.
   */

    return new JdkMatcher(pattern.matcher(t));
  }

  @Override
  public String pattern() {
    return pattern.pattern();
  }

  @Override
  public int flags() {
    return pattern.flags();
  }

  @Override
  public String toString() {
    return pattern.toString();
  }

  private static final class JdkMatcher extends CommonMatcher {
    final Matcher matcher;