public function test() { $e1 = new Entity(['id' => 1]); $collection = new Collection([$e2 = new Entity(['id' => 2]), $e3 = new Entity(['id' => 3])]); $collection->prepend($e1); $this->assertEquals([['id' => 1], ['id' => 2], ['id' => 3]], $collection->toArray()); }