@Test
public void getValueForSingleDatatypeWithMultipleValue() throws ValidationException {

    QName qn = new QName(DatatypeFactory.NS_XSD, "xs:string");
    Datatype dt = instance.getDatatype(qn);
    assertFalse("xs:string allows multiple", dt.allowsMultiple());
    String inputValue="1, 2, 3";
    XdmValue value = dt.convert(inputValue, saxonConfiguration);
    assertEquals(inputValue+" do not produces a single value", 1, value.size());
    assertEquals(inputValue, value.toString());
}