@Test
public void test_get_parameter_values_as_string_not_null_single_values() throws Exception{

    bo.setValue("a value ");
    when(dataObjectService.find(Matchers.argThat(new ClassOrSubclassMatcher<ParameterBo>(
            ParameterBo.class)), any(QueryByCriteria.class))).thenReturn(bo);
    Collection<String> paramValueList = getParameterRepositoryService().getParameterValuesAsString(key);
    assertTrue(paramValueList != null && paramValueList.size() == 1 &&
                  paramValueList.contains("a value"));
    assertImmutableList(paramValueList);
    verify(dataObjectService, times(1)).find(Matchers.argThat(new ClassOrSubclassMatcher<ParameterBo>(
            ParameterBo.class)), any(QueryByCriteria.class));
}