Author: Tobias Nyholm (tobias.nyholm@gmail.com)
Inheritance: implements Psr\Cache\CacheItemPoolInterface
 public function testCommit()
 {
     $namespace = 'ns';
     $returnValue = true;
     $stub = $this->getHierarchyCacheStub();
     $stub->expects($this->once())->method('commit')->willReturn($returnValue);
     $pool = new NamespacedCachePool($stub, $namespace);
     $this->assertEquals($returnValue, $pool->commit());
 }