class MutableSpan implements Cloneable {

  public boolean debug() {
    return (flags & FLAG_DEBUG) == FLAG_DEBUG;
  }

}

class MutableSpanTest {

  static final Pattern CREDIT_CARD;
  static final Exception EX1;
  public static List<Supplier<MutableSpan>> PERMUTATIONS;

  @Test public void debug() {

    MutableSpan span = new MutableSpan();
    span.setDebug();
    assertThat(span.debug()).isTrue();

    span.unsetDebug();
    assertThat(span.debug()).isFalse();
    assertThat(span.flags).isZero();
  }

}