private void removeMapping(Shell shell) {
    TableItem[] itemsIdMaps = fIdMapsTable.getSelection();
    TableItem[] itemsMappings = fMappingsTable.getSelection();

    if (itemsMappings.length > 0 && itemsIdMaps.length > 0) {
      Mapping mapping = (Mapping) itemsMappings[0].getData();
      IdMap idmap = (IdMap) itemsIdMaps[0].getData();
      HashMap idmapHS = (HashMap) fIdMaps.get(idmap.getName());
      idmapHS.remove(mapping.getKey());
      Vector mappings = idmap.getMappings();
      mappings.remove(mapping);
      itemsMappings[0].dispose(); // Table is single selection
    }
  }