phpstreams\tests\unit\FunctionsTest::testIdentity PHP Method

    public function testIdentity()
    {
        $data = ['foo', 'bar', 42];
        $identityFunc = Functions::identity();
        $this->assertTrue(is_callable($identityFunc), "Identity function should be callable.");
        foreach ($data as $item) {
            $this->assertEquals($item, $identityFunc($item));
        }
    }