public function testImportCountableRecords()
{
$records = $this->porter->import(new StaticDataImportSpecification(new \ArrayIterator(range(1, $count = 10))));
// Innermost collection.
self::assertInstanceOf(\Countable::class, $first = $records->findFirstCollection());
self::assertCount($count, $first);
// Outermost collection.
self::assertInstanceOf(\Countable::class, $records);
self::assertCount($count, $records);
}