public function testAppendCollection()
 {
     $entity1 = $this->createEntityMock();
     $entity2 = $this->createEntityMock();
     $entity3 = $this->createEntityMock();
     $entity4 = $this->createEntityMock();
     $entity5 = $this->createEntityMock();
     $col1 = new Collection(array($entity1, $entity2, $entity3));
     $col2 = new Collection(array($entity4, $entity5));
     $col1->appendCollection($col2);
     $this->assertCount(5, $col1);
     $this->assertSame($entity4, $col1->getAt(3));
     $this->assertSame($entity5, $col1->getAt(4));
 }