@Test
public void testJoin()
{

    DataElement deA = new DataElement( "DEA" );
    DataElement deB = new DataElement( "DEB" );
    DataElement deC = new DataElement( "DEC" );
    
    String expected = deA.getDisplayName() + SEPARATOR_JOIN + deB.getDisplayName() + SEPARATOR_JOIN + deC.getDisplayName();
    
    assertEquals( expected, IdentifiableObjectUtils.join( Lists.newArrayList( deA, deB, deC ) ) );
    assertNull( IdentifiableObjectUtils.join( null ) );
    assertNull( IdentifiableObjectUtils.join( Lists.newArrayList() ) );        
}