title: Cell reuse bug in collectionView
body: <p>Hello to all dear friends. I'm experiencing a problem with cell reuse. In practice I select multiple cells. In the "didSelected" method, I modify a property, called "isSelectedCell", to true and add a green border (to indicate the selection); While in the "didDeselect" method I carry it to false and remove the color of the border. But when I scroll down some cells, never selected, appear to be selected and the property is true. Because? How do I prevent this. It seems that when a cell is reused, the properties take on old ones and not their own.</p>