'bar', 'baz' => 'qux'], ['bar', 'qux']]; yield [[], []]; yield [['hello', 'world'], ['hello', 'world']]; yield [new Collection\Vector([1, 2, 3]), [1, 2, 3]]; yield [new Collection\Vector([null]), [null]]; yield [new Collection\Map(['foo' => 'bar', 'baz' => 'qux']), ['bar', 'qux']]; yield [new Collection\Map([]), []]; yield [new Collection\MutableVector(['hello', 'world']), ['hello', 'world']]; yield [$this->createGeneratorFromIterable([1, 2, 3]), [1, 2, 3]]; yield [$this->createGeneratorFromIterable([null]), [null]]; yield [$this->createGeneratorFromIterable(['foo' => 'bar', 'baz' => 'qux']), ['bar', 'qux']]; yield [$this->createGeneratorFromIterable([]), []]; yield [$this->createGeneratorFromIterable(['hello', 'world']), ['hello', 'world']]; } private function createGeneratorFromIterable(iterable $iterable): iterable { foreach ($iterable as $k => $v) { yield $k => $v; } } }