@Override
 public String getText(Object element) {
   if (element instanceof Exclusion) {
     Exclusion exclusion = (Exclusion) element;
     switch (columnIndex) {
       case 0:
         return exclusion.getGroupId();
       case 1:
         return exclusion.getArtifactId();
     }
   }
   return null;
 }
 @Override
 protected Object getValue(Object element) {
   Exclusion exclusion = (Exclusion) element;
   String value = null;
   switch (this.column) {
     case 0:
       value = exclusion.getGroupId();
       if (value == null) {
         value = ""; // $NON-NLS-1$
       }
       return value;
     case 1:
       value = exclusion.getArtifactId();
       if (value == null) {
         value = ""; // $NON-NLS-1$
       }
       return value;
   }
   return null;
 }