/**
  * This method tests the "nvl" method.
  */
 public function test_nvl()
 {
     $x = IInteger\Type::one();
     $y = IInteger\Type::zero();
     $z = IInteger\Module::nvl($x, $y);
     $this->assertInstanceOf('\\Saber\\Data\\IInteger\\Type', $z);
     $this->assertSame('1', $z->unbox());
     $z = IInteger\Module::nvl(null, $x);
     $this->assertInstanceOf('\\Saber\\Data\\IInteger\\Type', $z);
     $this->assertSame('1', $z->unbox());
     $z = IInteger\Module::nvl(null, null);
     $this->assertInstanceOf('\\Saber\\Data\\IInteger\\Type', $z);
     $this->assertSame('0', $z->unbox());
 }