public function testIsSwapCheckOn()
 {
     $memUsage = new MemoryUsage(new DI());
     $this->assertTrue($memUsage->isSwapCheckOn(), 'MemoryUsage::isSwapCheckOn default true value test failed!');
     $memUsage = new MemoryUsage(new DI());
     $memUsage->setSwapCheckOn(false);
     $this->assertFalse($memUsage->isSwapCheckOn(), 'MemoryUsage::isSwapCheckOn test failed!');
 }