let cards = [
{id: 0, cardState: CardState.HIDING, backgroundColor: 'red'},
{id: 1, cardState: CardState.HIDING, backgroundColor: 'red'},
{id: 2, cardState: CardState.HIDING, backgroundColor: 'navy'},
{id: 3, cardState: CardState.HIDING, backgroundColor: 'navy'},
{id: 4, cardState: CardState.HIDING, backgroundColor: 'green'},
{id: 5, cardState: CardState.HIDING, backgroundColor: 'green'},
{id: 6, cardState: CardState.HIDING, backgroundColor: 'yellow'},
{id: 7, cardState: CardState.HIDING, backgroundColor: 'yellow'},
{id: 8, cardState: CardState.HIDING, backgroundColor: 'black'},
{id: 9, cardState: CardState.HIDING, backgroundColor: 'black'},
{id: 10, cardState: CardState.HIDING, backgroundColor: 'purple'},
{id: 11, cardState: CardState.HIDING, backgroundColor: 'purple'},
{id: 12, cardState: CardState.HIDING, backgroundColor: 'pink'},
{id: 13, cardState: CardState.HIDING, backgroundColor: 'pink'},
{id: 14, cardState: CardState.HIDING, backgroundColor: 'lightskyblue'},
{id: 15, cardState: CardState.HIDING, backgroundColor: 'lightskyblue'}
];
this.state = {cards: shuffle(cards)};