*       domain).equals(ContiguousSet.create(b, domain))} implies {@code
   *       a.canonical(domain).equals(b.canonical(domain))}
   *   <li>idempotence: {@code a.canonical(domain).canonical(domain).equals(a.canonical(domain))}
   * </ul>
   *
   * <p>Furthermore, this method guarantees that the range returned will be one of the following
   * canonical forms:
   *
   * <ul>
   *   <li>[start..end)
   *   <li>[start..+∞)

    assertEquals(Range.closedOpen(Integer.MIN_VALUE, 0), Range.lessThan(0).canonical(integers()));
    assertEquals(Range.closedOpen(Integer.MIN_VALUE, 1), Range.atMost(0).canonical(integers()));
    assertEquals(Range.atLeast(0), Range.atLeast(0).canonical(integers()));
    assertEquals(Range.atLeast(1), Range.greaterThan(0).canonical(integers()));

    public E intern(E sample) {
      while (true) {
        // trying to read the canonical...
        @SuppressWarnings("rawtypes") // using raw types to avoid a bug in our nullness checker :(
        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {
          Object canonical = entry.getKey();
          if (canonical != null) { // only matters if weak/soft keys are used

  public void testWeak_afterGC() throws InterruptedException {
    Integer canonical = new Integer(5);
    Integer not = new Integer(5);

    Interner<Integer> pool = Interners.newWeakInterner();
    assertSame(canonical, pool.intern(canonical));

    WeakReference<Integer> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);

  public void testWeak_afterGC() throws InterruptedException {
    Integer canonical = new Integer(5);
    Integer not = new Integer(5);

    Interner<Integer> pool = Interners.newWeakInterner();
    assertSame(canonical, pool.intern(canonical));

    WeakReference<Integer> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);

  @CheckForNull
  abstract C greatestValueBelow(DiscreteDomain<C> domain);

  /*
   * The canonical form is a BelowValue cut whenever possible, otherwise ABOVE_ALL, or
   * (only in the case of types that are unbounded below) BELOW_ALL.
   */
  Cut<C> canonical(DiscreteDomain<C> domain) {
    return this;
  }

  // note: overridden by {BELOW,ABOVE}_ALL
  @Override

    assertEquals(Range.closedOpen(Integer.MIN_VALUE, 0), Range.lessThan(0).canonical(integers()));
    assertEquals(Range.closedOpen(Integer.MIN_VALUE, 1), Range.atMost(0).canonical(integers()));
    assertEquals(Range.atLeast(0), Range.atLeast(0).canonical(integers()));
    assertEquals(Range.atLeast(1), Range.greaterThan(0).canonical(integers()));

  @CheckForNull
  abstract C greatestValueBelow(DiscreteDomain<C> domain);

  /*
   * The canonical form is a BelowValue cut whenever possible, otherwise ABOVE_ALL, or
   * (only in the case of types that are unbounded below) BELOW_ALL.
   */
  Cut<C> canonical(DiscreteDomain<C> domain) {
    return this;
  }

  // note: overridden by {BELOW,ABOVE}_ALL
  @Override

    public E intern(E sample) {
      while (true) {
        // trying to read the canonical...
        @SuppressWarnings("rawtypes") // using raw types to avoid a bug in our nullness checker :(
        InternalEntry entry = map.getEntry(sample);
        if (entry != null) {
          Object canonical = entry.getKey();
          if (canonical != null) { // only matters if weak/soft keys are used

        // Pass
      }
    }
  }

  public void testFalsePositivesForNextEscapedIndex() {
    UnicodeEscaper e =
        new UnicodeEscaper() {
          // Canonical escaper method that only escapes lower case ASCII letters.
          @Override
          protected char @Nullable [] escape(int cp) {