@Test
public void invalidStringConversion() {

    assertThat(InstanceCoordinate.parse("foo:bar.baz"), is(nullValue()));
    assertThat(InstanceCoordinate.parse(null), is(nullValue()));
    assertThat(InstanceCoordinate.parse("foo.bar.baz"), is(nullValue()));
    assertThat(InstanceCoordinate.parse(""), is(nullValue()));
}