in QuizDemo/QuizDemo/Controllers/PlayerViewController.swift [110:120]
func showWaitingLabel() {
waitingLabel.isHidden = false
waitingLabelHeightConstraint.constant = 25
UIView.animate(withDuration: 3,
delay: 0,
options: [.curveEaseInOut, .repeat, .autoreverse],
animations: { [weak self] in
self?.waitingLabelHeightConstraint.constant = 50
self?.view.layoutIfNeeded()
})
}