@Test
public void testFactories() {

    assertThat(of(null, null, null))
            .extracting(DataFormat::getLocale, DataFormat::getDatePattern, DataFormat::getNumberPattern)
            .containsExactly(null, "", "");
    assertThat(of(FRENCH, null, null))
            .extracting(DataFormat::getLocale, DataFormat::getDatePattern, DataFormat::getNumberPattern)
            .containsExactly(FRENCH, "", "");
    assertThat(of(null, "yyyy", null))
            .extracting(DataFormat::getLocale, DataFormat::getDatePattern, DataFormat::getNumberPattern)
            .containsExactly(null, "yyyy", "");
    assertThat(of(null, null, "#0.00"))
            .extracting(DataFormat::getLocale, DataFormat::getDatePattern, DataFormat::getNumberPattern)
            .containsExactly(null, "", "#0.00");
}