function addCards(item){
  let card = item.firstElementChild.className;
      
  cardsCollection.push(card);
}
/*
* Invoked by activateCard().
* Add clicked card to cards collection array.
* @param {object} item - Target of event listener
*/
Invoked by activateCard().
Add clicked card to cards collection array.
Invoked by activateCard () . Add clicked card to cards collection array .
function addCards(item){
  let card = item.firstElementChild.className;
  cardsCollection.push(card);
}
function addCards ( item ) { let card = item . firstElementChild . className ; cardsCollection . push ( card ) ; }
Invoked by activateCard().
Invoked by activateCard () .