try {
      Utf8.encodedLength(invalidString);
      fail();
    } catch (IllegalArgumentException expected) {
      assertThat(expected)
          .hasMessageThat()
          .isEqualTo("Unpaired surrogate at index " + invalidCodePointIndex);
    }
  }

  // 128 - [chars 0x0000 to 0x007f]

        assertThrows(
            AssertionFailedError.class,
            () ->
                new EqualsTester().addEqualityGroup(new EqualsBasedOnToString("foo")).testEquals());
    assertThat(e).hasMessageThat().contains("toString representation");
  }

  private static void assertErrorMessage(Throwable e, String message) {
    // TODO(kevinb): use a Truth assertion here
    if (!e.getMessage().contains(message)) {

            () -> {
              BloomFilter<String> unused =
                  BloomFilter.create(HashTestUtils.BAD_FUNNEL, Integer.MAX_VALUE, Double.MIN_VALUE);
            });
    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("Could not create BloomFilter of 3327428144502 bits");
  }

  @AndroidIncompatible // OutOfMemoryError
  public void testLargeNumberOfInsertions() {

    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> builder.addAll(nCopies(Integer.MAX_VALUE - 50, "a")));
    assertThat(expected)
        .hasMessageThat()
        .contains("cannot store more than Integer.MAX_VALUE elements");
  }

    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> builder.addAll(nCopies(Integer.MAX_VALUE - 50, "a")));
    assertThat(expected)
        .hasMessageThat()
        .contains("cannot store more than Integer.MAX_VALUE elements");
  }

    // being true.
    Pattern pattern = Pattern.compile("Multiple entries with same key: four=(.*) and four=(.*)");
    assertThat(expected).hasMessageThat().matches(pattern);
    Matcher matcher = pattern.matcher(expected.getMessage());
    assertThat(matcher.matches()).isTrue();
    assertThat(matcher.group(1)).isNotEqualTo(matcher.group(2));
  }

    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> Maps.uniqueIndex(ImmutableSet.of("one", "uno"), Functions.constant(1)));
    assertThat(expected).hasMessageThat().contains("Multimaps.index");
  }

  /** Null values are not allowed. */
  public void testUniqueIndexNullValue() {
    List<@Nullable String> listWithNull = Lists.newArrayList((String) null);
    assertThrows(

    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> Maps.uniqueIndex(ImmutableSet.of("one", "uno"), Functions.constant(1)));
    assertThat(expected).hasMessageThat().contains("Multimaps.index");
  }

  /** Null values are not allowed. */
  public void testUniqueIndexNullValue() {
    List<@Nullable String> listWithNull = Lists.newArrayList((String) null);
    assertThrows(