@Test public void
shouldSetAllowedValues()
{

    final String aV1 = "av1";
    final String aV2 = "aV2";
    Constraint constraint = new Constraint("name", aV1);
    assertThat(constraint.getAllowedValues(),hasSize(1));
    assertThat(constraint.getAllowedValues(),hasItem(aV1));
    constraint = new Constraint("name",aV1,aV2);
    assertThat(constraint.getAllowedValues(),hasSize(2));
    assertThat(constraint.getAllowedValues(),hasItem(aV1));
    assertThat(constraint.getAllowedValues(),hasItem(aV2));
}