anchor.diff:            <AddGroupButton refresh={this.props.refresh} />
             <div className={'wrapRightGroups'}>
               <Table data={groups_data} columns={columns} filters={filters} 
  +              selectable={true}
  +              onSelectedRowsChange={this.props.onSelectedGroupsChange}
                 search_placeholder={'<%= j raw I18n.t('groups.search_groups') %>'} />
             </div>
           </div>
  
positive.code:       var groups_data = this.props.groups.map(function(group) {
          var g = {};
          g['id'] = group.id;
          g['checkbox'] = <input id={group.id} type='checkbox'
            checked={this.props.selected_groups.indexOf(group.id) !== -1 ? true : false}
            onChange={this.groupCheckboxClicked} />
          g['name'] = group.name;
          var links = [];
          if (group.valid) {
  
negative.code: 
    // The table of groups on the right.
    var GroupsTable = React.createClass({
      studentCheckboxClicked: function(event) {
        var value = event.currentTarget.checked;
        var group_student_id = parseInt(event.currentTarget.getAttribute('id'));
  