@Test
public void writeMandatory()
                        throws XMLStreamException {

    final String frame = null;
    final String calendarEraName = null;
    final IndeterminateValue indeterminatePosition = null;
    final String value = null;
    final TimePosition timePosition = new TimePosition( frame, calendarEraName, indeterminatePosition, value );
    final MemoryXmlStreamWriter xmlWriter = new MemoryXmlStreamWriter();
    xmlWriter.writeEmptyElement( "TimePosition" );
    gmlTimePositionTypeWriter.write( timePosition, xmlWriter );
    xmlWriter.close();
    assertEquals( "<TimePosition/>", xmlWriter.getOutput() );
}