public function __toString() : string { if ($this->isEmpty()) { return 'Ø'; } return 'Set{' . implode(', ', array_keys($this->A)) . '}'; }
/** * @dataProvider dataProviderForToString */ public function testToString(array $members, string $expected) { $set = new Set($members); $this->assertEquals($expected, $set->__toString()); }