title: Smartgwt ListGrid Group order
body: <p>I have a ListGrid with 3 columns, one is hidden but it doesn't change anything to the problem.
  I want to group on the value of the 3rd and hidden field, a date. When this Date is not present (null) I want to put the record in the "Actual Projects" group else they go in the "Closed projects" group.
  It works BUT I want to have the group Actual Project first and I try a lot of thing with the sort direction of the field and the grid and also with <code>baseTitle</code> I return. It never change I always have the group with the non null value first.
  Am I missing something? Is there somebody who experienced with group order?</p>
  
  <pre><code>   final int groupClosed = 2;
      final int groupActual = 1;
  
  
      colonneDate.setGroupValueFunction(new GroupValueFunction() {  
          public Object getGroupValue(Object value, ListGridRecord record, ListGridField field, String fieldName, ListGrid grid) {  
              Date laDate = (Date)value;            
              if(laDate == null) {  
                  return groupActual;  
              } else {  
                  return groupClosed;  
              }
          }  
      });  
      colonneDate.setGroupTitleRenderer(new GroupTitleRenderer() {
  
          @Override
          public String getGroupTitle(Object groupValue, GroupNode groupNode,
                  ListGridField field, String fieldName, ListGrid grid) {
              final int groupType = (Integer) groupValue;
               String baseTitle ="";
  
              switch (groupType){
              case groupActual:
                   baseTitle ="Actual Projects";
                  break;
              case groupClosed:
                    baseTitle ="Closed Projects";
                  break;
  
              }           
              return baseTitle;
          }             
      });  
  
  
  listeGridProjets.setGroupByField("date");
  </code></pre>