public function testEmpty() { $map = new Map(["a" => 1, "b" => 2, "c" => 3, "d" => 3]); $this->assertFalse($map->isEmpty()); $map = new Map(["a" => null]); $this->assertFalse($map->isEmpty()); $map = new Map([]); $this->assertTrue($map->isEmpty()); }