protected function extractFilter(Block $block, array &$filter, array &$excluded)
    {
        if (isset($block->filter['+'])) {
            foreach ($block->filter['+'] as $filterValue) {
                if (isset($filter[$filterValue])) {
                    $filter[$filterValue][$block->id] = true;
                } else {
                    $filter[$filterValue] = [$block->id => true];
                }
            }
        }
        if (isset($block->filter['-'])) {
            foreach ($block->filter['-'] as $filterValue) {
                if (isset($filter[$filterValue])) {
                    $filter[$filterValue][$block->id] = false;
                } else {
                    $filter[$filterValue] = [$block->id => false];
                }
                // By default block with - should display on all sited except those from filter
                $excluded[$block->id] = true;
            }
        }
    }