assertThat(e).hasMessageThat().isEqualTo("A (Object[])null C");
  }

  public void testCheckArgument_complexMessage_success() {
    checkArgument(true, "%s", IGNORE_ME);
  }

  public void testCheckArgument_complexMessage_failure() {
    IllegalArgumentException expected =
        assertThrows(IllegalArgumentException.class, () -> checkArgument(false, FORMAT, 5));
    verifyComplexMessage(expected);
  }