public function testUcServiceSelector()
 {
     $value = $this->faker->word;
     $ucs = new UcServiceSelector(UcServiceBy::ID(), $value);
     $this->assertSame('id', $ucs->getBy()->value());
     $ucs->setBy(UcServiceBy::NAME());
     $this->assertSame('name', $ucs->getBy()->value());
     $xml = '<?xml version="1.0"?>' . "\n" . '<ucservice by="' . UcServiceBy::NAME() . '">' . $value . '</ucservice>';
     $this->assertXmlStringEqualsXmlString($xml, (string) $ucs);
     $array = ['ucservice' => ['by' => UcServiceBy::NAME()->value(), '_content' => $value]];
     $this->assertEquals($array, $ucs->toArray());
 }