@Test public void testIsSuccess() {

    assertThat(new IabResult(0, "OK").isSuccess()).isTrue();
    assertThat(new IabResult(0, "OK").isFailure()).isFalse();
    assertThat(new IabResult(1, "FAIL").isSuccess()).isFalse();
    assertThat(new IabResult(1, "FAIL").isFailure()).isTrue();
}