Neos\Flow\Aop\Pointcut\PointcutClassNameFilter::reduceTargetClassNames PHP Method

    public function reduceTargetClassNames(ClassNameIndex $classNameIndex)
    {
        if (!preg_match('/^([^\\.\\(\\)\\{\\}\\[\\]\\?\\+\\$\\!\\|]+)/', $this->originalExpressionString, $matches)) {
            return $classNameIndex;
        }
        $prefixFilter = $matches[1];
        // We sort here to make sure the index is okay
        $classNameIndex->sort();
        return $classNameIndex->filterByPrefix($prefixFilter);
    }

 /**
  * @test
  */
 public function reduceTargetClassNamesFiltersAllClassesNotMatchedByAClassNameFilterWithRegularExpressions()
 {
     $availableClassNames = ['TestPackage\\Subpackage\\Class1', 'TestPackage\\Class2', 'TestPackage\\Subpackage\\SubSubPackage\\Class3', 'TestPackage\\Subpackage2\\Class4'];
     sort($availableClassNames);
     $availableClassNamesIndex = new Aop\Builder\ClassNameIndex();
     $availableClassNamesIndex->setClassNames($availableClassNames);
     $expectedClassNames = ['TestPackage\\Subpackage\\Class1', 'TestPackage\\Subpackage\\SubSubPackage\\Class3'];
     sort($expectedClassNames);
     $expectedClassNamesIndex = new Aop\Builder\ClassNameIndex();
     $expectedClassNamesIndex->setClassNames($expectedClassNames);
     $classNameFilter = new Aop\Pointcut\PointcutClassNameFilter('TestPackage\\Subpackage\\.*');
     $result = $classNameFilter->reduceTargetClassNames($availableClassNamesIndex);
     $this->assertEquals($expectedClassNamesIndex, $result, 'The wrong class names have been filtered');
 }