code: public function filter(ScopeInterface $scope)
      {
          $filtered = new self;
  
          foreach ($this as $eachResult) {
              /* @var $eachResult ResultInterface */
              if ($eachResult->getScope()->isEqualTo($scope)) {
                  $filtered->add($eachResult);
              }
          }
  
          return $filtered;
      }
docs: Filter the currect set of results by the given scope.
  
  @param ScopeInterface $scope
  
  @return ResultCollection|ResultInterface[]