How to add sort by number of votes in admin?
I have a nominee entity with relation One To Many vote. I need to allow to sort by number of votes for nominees.
I try a solution from here: https://github.com/sonata-project/SonataAdminBundle/issues/1077 and first here: Sonata Admin Bundle: show total count of collection on list view
But I get error message: [Semantical Error] line 0, col 184 near 'v_id_count ASC,': Error: 'v_id_count' is not defined.
Here's the code from NomineeAdmin:
public function createQuery($context = 'list')
{
    $query = parent::createQuery($context);
    if ('list' === $context) {
        $parameters = $this->getFilterParameters();
        if ('getVotesCount' === $parameters['_sort_by']) {
            $rootAlias = $query->getRootAliases()[0];
            $query
                ->addSelect('COUNT(v.id) as v_id_count')
                ->leftJoin($rootAlias . '. votes', 'v')
                ->groupBy($rootAlias . '.id')
                ->orderBy('v_id_count', $parameters['_sort_order']);
        }
    }
    return $query;
}
protected function configureListFields(ListMapper $listMapper)
{
    $listMapper
        //...
        ->add(
            'getVotesCount',
            null,
            [
                'sortable'                         => true,
                'sort_field_mapping'               => ['fieldName' => 'id'],
                'sort_parent_association_mappings' => [],
            ]
        );
}