protected internal ArrayList SortListForVerticalPosition(ArrayList sequenceChartElements)
 {
     ArrayList orderedSequenceChartElements=null;
     SequenceChartElementListSorter elementListSorter=
             new SequenceChartElementListSorter();
     orderedSequenceChartElements=elementListSorter.SortListForVerticalPosition(sequenceChartElements);
     return orderedSequenceChartElements;
 }