public function testSearch() { $collection = new Collection(['a' => 'x', 'b' => 'Y']); $this->assertEquals('a', $collection->search('x')); $this->assertEquals('a', $collection->search('X')); $this->assertEquals(null, $collection->search('X', true)); $this->assertEquals('b', $collection->search('y')); $this->assertEquals(null, $collection->search('y', true)); }