@Test
public void nulls() throws Exception {

    assertThat(ContentRange.parse(null)).isNull();
    assertThat(ContentRange.parse("awefss")).isNull();
    assertThat(ContentRange.parse("items   1/")).isNull();
    assertThat(ContentRange.parse("items 1/2")).isNull();
    assertThat(ContentRange.parse("items1-3/2")).isNull();
    assertThat(ContentRange.parse("items232dsf")).isNull();
}