assertThat(Booleans.trueFirst().compare(true, true)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(false, false)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(true, false)).isLessThan(0);
    assertThat(Booleans.trueFirst().compare(false, true)).isGreaterThan(0);
  }

  public void testFalseFirst() {
    assertThat(Booleans.falseFirst().compare(true, true)).isEqualTo(0);

  public void testContains_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Predicates.contains(Pattern.compile("foo")), Predicates.containsPattern("foo"))
        .addEqualityGroup(Predicates.contains(Pattern.compile("foo", Pattern.CASE_INSENSITIVE)))
        .addEqualityGroup(Predicates.containsPattern("bar"))
        .testEquals();
  }

  public void assertEqualHashCode(

    }
  }

  /**
   * Returns an immutable list containing the given elements, sorted according to their natural
   * order. The sorting algorithm used is stable, so elements that compare as equal will stay in the
   * order in which they appear in the input.
   *
   * <p>If your data has no duplicates, or you wish to deduplicate elements, use {@code

   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Elements that compare equal are considered equal and no new permutations are created by
   * swapping them.
   *
   * <p>An empty iterable has only one permutation, which is an empty list.
   *

    }
  }

  public void testCompare() {
    for (long a : UNSIGNED_INTS) {
      for (long b : UNSIGNED_INTS) {
        int cmpAsLongs = Longs.compare(a, b);
        int cmpAsUInt = UnsignedInts.compare((int) a, (int) b);
        assertThat(Integer.signum(cmpAsUInt)).isEqualTo(Integer.signum(cmpAsLongs));
      }
    }
  }

  public void testMax_noArgs() {
    try {

   * call {@code supplier} or invoke {@code function} until it is called.
   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {
    return new SupplierComposition<>(function, supplier);
  }

  private static class SupplierComposition<F extends @Nullable Object, T extends @Nullable Object>

    if (roundArbitrarilyAsLong == Long.MAX_VALUE) {
      /*
       * For most values, the conversion from roundArbitrarily to roundArbitrarilyAsLong is
       * lossless. In that case we can compare x to roundArbitrarily using Longs.compare(x,
       * roundArbitrarilyAsLong). The exception is for values where the conversion to double rounds
       * up to give roundArbitrarily equal to 2^63, so the conversion back to long overflows and

    }
  }

  private static <K extends Enum<K>, V> ImmutableMap<K, ? extends V> copyOfEnumMap(
      EnumMap<?, ? extends V> original) {
    @SuppressWarnings("unchecked") // the best we could do to make copyOf(Map) compile
    EnumMap<K, V> copy = new EnumMap<>((EnumMap<K, ? extends V>) original);
    for (Entry<K, V> entry : copy.entrySet()) {
      checkEntryNotNull(entry.getKey(), entry.getValue());
    }

         * just one problem: Starting with JDK 7u51, the JDK TypeVariable's equals() method doesn't
         * recognize instances of our TypeVariable implementation. This is a problem because users
         * compare TypeVariables from the JDK against TypeVariables returned by TypeResolver. To
         * work with all JDK versions, TypeResolver must return the appropriate TypeVariable
         * implementation in each of the three possible cases:

                    Collections.sort(
                        insertionOrder,
                        new Comparator<Entry<String, Integer>>() {
                          @Override
                          public int compare(Entry<String, Integer> o1, Entry<String, Integer> o2) {
                            return o1.getKey().compareTo(o2.getKey());
                          }
                        });
                    return insertionOrder;