// should be unequal to empty.
  public void testEquals() {
    TreeRangeMap<Integer, Integer> empty = TreeRangeMap.create();
    TreeRangeMap<Integer, Integer> nonEmpty = TreeRangeMap.create();
    nonEmpty.put(Range.all(), 1);
    TreeRangeMap<Integer, Integer> coalesced = TreeRangeMap.create();
    coalesced.put(Range.atLeast(1), 1);
    coalesced.putCoalescing(Range.atMost(1), 1);

    return Platform.nullToEmpty(string);
  }

  /**
   * Returns the given string if it is nonempty; {@code null} otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is nonempty; {@code null} if it is empty or null
   */
  public static @Nullable String emptyToNull(@Nullable String string) {
    return Platform.emptyToNull(string);

      return -1;
    } else {
      return (int) value;
    }
  }

  /**
   * Returns the least value present in {@code array}, treating values as unsigned.
   *
   * @param array a <i>nonempty</i> array of unsigned {@code int} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array according to {@link #compare}

  public static int compare(long a, long b) {
    return Longs.compare(flip(a), flip(b));
  }

  /**
   * Returns the least value present in {@code array}, treating values as unsigned.
   *
   * @param array a <i>nonempty</i> array of unsigned {@code long} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array according to {@link #compare}

/**
 * A collection that maps keys to values, similar to {@link Map}, but in which each key may be
 * associated with <i>multiple</i> values. You can visualize the contents of a multimap either as a
 * map from keys to <i>nonempty</i> collections of values:
 *
 * <ul>
 *   <li>a → 1, 2
 *   <li>b → 3
 * </ul>
 *
 * ... or as a single "flattened" collection of key-value pairs:
 *
 * <ul>
 *   <li>a → 1
 *   <li>a → 2

  public ImmutableRangeSet<C> difference(RangeSet<C> other) {
    RangeSet<C> copy = TreeRangeSet.create(this);
    copy.removeAll(other);
    return copyOf(copy);
  }

  /**
   * Returns a list containing the nonempty intersections of {@code range} with the ranges in this
   * range set.
   */
  private ImmutableList<Range<C>> intersectRanges(Range<C> range) {
    if (ranges.isEmpty() || range.isEmpty()) {

      if (array[i] == target) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Returns the least value present in {@code array}.
   *
   * @param array a <i>nonempty</i> array of {@code char} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array
   * @throws IllegalArgumentException if {@code array} is empty
   */

      if (array[i] == target) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Returns the least value present in {@code array}.
   *
   * @param array a <i>nonempty</i> array of {@code short} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array
   * @throws IllegalArgumentException if {@code array} is empty
   */

      if (array[i] == target) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Returns the least value present in {@code array}.
   *
   * @param array a <i>nonempty</i> array of {@code short} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array
   * @throws IllegalArgumentException if {@code array} is empty
   */

      int r = rng.nextInt(); // Avoid zero to allow xorShift rehash
      h = hc[0] = (r == 0) ? 1 : r;
    } else h = hc[0];
    boolean collide = false; // True if last slot nonempty
    for (; ; ) {
      Cell[] as;
      Cell a;
      int n;
      long v;
      if ((as = cells) != null && (n = as.length) > 0) {
        if ((a = as[(n - 1) & h]) == null) {